Search

Background: There are little data on changes in insulin sensitivity during the first few years of life following in utero human immunodeficiency virus (HIV) and antiretroviral (ARV) exposure., Methods: The Tshilo Dikotla study enrolled pregnant persons with HIV (PWH) (receiving tenofovir/emtricitabine or lamivudine plus dolutegravir or efavirenz) and pregnant individuals without HIV, as well as their liveborn children. Newborns were randomized to receive either zidovudine (AZT) or nevirapine (NVP) postnatal prophylaxis. Homeostasis Model Assessment for Insulin Resistance (HOMA-IR) was assessed at birth and 1, 18, 24, and 36 months of life. We fit linear mixed-effects models to evaluate the association between in utero HIV/ARV exposure and average HOMA-IR from birth through 36 months of life, adjusting for confounders., Results: A total of 419 children were included (287 with in utero HIV/ARV exposure and uninfected [CHEU] and 132 without in utero HIV/ARV exposure [CHUU]). CHEU were born to older women (29.6 vs 25.3 years of age) with higher gravidity (3 vs 1). HOMA-IR was persistently higher in CHEU versus CHUU in adjusted analyses (mean difference of 0.07 in log10 HOMA-IR, P = .02) from birth through 36 months of life. Among CHEU, no differences in HOMA-IR were observed from birth through 36 months by in utero ARV exposure status or between AZT and NVP infant prophylaxis arms., Conclusions: In utero HIV/ARV exposure was associated with lower insulin sensitivity throughout the first 36 months of life, indicating persistent early life metabolic disturbances which may raise concern for poorer metabolic health later in life., Competing Interests: Potential conflicts of interest. M. E. G. has clinical trial contracts with Adrenas, Ascendis, Diurnal, Neurocrine Biosciences, Novo Nordisk, Pfizer, and Spruce Biosciences; is a consultant for Adrenas, Aeterna Zentaris, Ascendis, Eton Pharmaceuticals, Neurocrine Biosciences, Novo Nordisk, Pfizer, and Spruce Biosciences; and receives royalties from McGraw-Hill and UpToDate; payment or honoraria for lectures, presentations, speaker’s bureaus, manuscript writing or educational events from Eton Pharmaceuticals. I. J. K. reports the following grants or contracts: NIH grant number P60DK020541. K. M. P. reports grants or contracts from NICHD and NIAID. All other authors report no potential conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (© The Author(s) 2024. Published by Oxford University Press on behalf of Infectious Diseases Society of America. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background: Weight gain is common after antiretroviral initiation, especially among females, those of black race and lower baseline CD4, although this may potentially be due to lower baseline weight. Use of tenofovir disoproxil fumarate or efavirenz can suppress weight gain., Methods: Data were pooled from the ADVANCE (n = 1053), NAMSAL (n = 613) and WHRI001 (n = 536) trials investigating first-line regimen. Week 96 weight and body mass index (BMI) was stratified by baseline CD4. Multivariable models of weight change and incident obesity (BMI ≥30 kg/m2) were adjusted for baseline CD4, age, sex, tenofovir disoproxil fumarate, efavirenz, baseline BMI and trial., Results: Participants across all treatment arms experienced weight gain from baseline to week 96, with baseline CD4 count, baseline HIV RNA, tenofovir alafenamide and dolutegravir use, and female sex significant predictors. Mean unadjusted weight change was highest with CD4 < 100 (+8.6 kg; SD = 8.2) and lowest with CD4 ≥ 350 (+3.0 kg; SD = 6.5). This weight gain in CD4 < 100 was highest for participants on tenofovir alafenamide-inclusive treatment, such that absolute weight at week 96 was highest in the CD4 < 100 group. Although not statistically significant, obesity rate (BMI ≥ 30 kg/m2) in those taking TAF/FTC + DTG with CD4 < 100 overtook that seen in CD4 ≥ 350, despite lower baseline obesity prevalence. The unadjusted findings were corroborated in multivariable longitudinal models., Conclusions: Participants with low CD4 may demonstrate significant 'overshoot' weight gain, in addition to 'return to health', with a trend towards increased risk of obesity when initiated on TAF/FTC + DTG. Use of tenofovir disoproxil fumarate and efavirenz were associated with smaller weight gains. Effective weight management strategies are needed, especially for individuals with low baseline CD4., (© The Author(s) 2024. Published by Oxford University Press on behalf of British Society for Antimicrobial Chemotherapy. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background: The late-onset efavirenz neurotoxicity syndrome (LENS) presents as ataxia and/or encephalopathy with supratherapeutic efavirenz plasma concentrations (>4 µg/mL). Efavirenz is primarily metabolized by cytochrome P450 2B6 (CYP2B6), with CYP2A6 as an accessory pathway. We hypothesized that participants with LENS would predominantly be CYP2B6 slow metabolizers. The aim of our study was to determine the frequency of CYP2B6 slow metabolizers in participants with LENS., Methods: Adult HIV-positive participants on efavirenz-based antiretroviral therapy presenting with LENS were prospectively enrolled. Genetic polymorphisms known to be associated with increased efavirenz plasma concentrations in CYP2B6 (rs3745274, rs28399499, rs4803419) and CYP2A6 (rs28399433) were selected and used to determine proportions of slow metabolizers. Pharmacokinetic analyses were performed using liquid chromatography-tandem mass spectrometry. Median (IQR) plasma efavirenz and 8-hydroxyefavirenz were described., Results: Fifteen participants were enrolled. Thirteen (13/15) were Black-African and 13 were female. Median weight was 49.9kg with a median duration on efavirenz of 2.2 years. All 15 participants were successfully genotyped as slow CYP2B6 metabolizers, with 6 participants additionally having CYP2A6 heterozygous genotype. Thirteen were receiving the CYP2A6 enzyme inhibitor isoniazid, and all 15 were genotypic NAT2 slow or intermediate acetylators. Efavirenz plasma concentration was markedly increased at 50.5 (47.0-65.4) µg/mL; 8-hydroxyefavirenz concentration was markedly decreased at 0.10 (0.07-0.15) µg/mL., Conclusions: Our cohort provides definitive evidence that LENS is associated with the CYP2B6 slow metabolizer genotype, with a median efavirenz plasma concentration >12-fold higher than the defined upper limit of the therapeutic range. Isoniazid and low body weight are important contributors to LENS development., Competing Interests: Potential conflicts of interest. All authors report no potential conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (© The Author(s) 2021. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Background: Dolutegravir is associated with more weight gain than efavirenz. Loss-of-function polymorphisms in CYP2B6 result in higher efavirenz concentrations, which we hypothesized would impair weight gain among people living with human immunodeficiency virus (HIV; PLWH) starting efavirenz-based antiretroviral therapy (ART)., Methods: We studied ART-naive participants from the ADVANCE study randomized to the efavirenz /emtricitabine/tenofovir disoproxil fumarate (TDF) and dolutegravir/emtricitabine/TDF arms. We compared changes in weight and regional fat on DXA from baseline to week 48 between CYP2B6 metabolizer genotypes in the efavirenz arm, and with the dolutegravir arm., Results: There were 342 participants in the dolutegravir arm and 168 in the efavirenz arm who consented to genotyping. Baseline characteristics were similar. Weight gain was greater in women than men. In the efavirenz arm CYP2B6 metaboliser genotype was associated with weight gain (P = .009), with extensive metabolizers gaining the most weight, and with changes in regional fat in women, but not in men. Weight gain was similar in CYP2B6 extensive metabolizers in the efavirenz arm and in the dolutegravir arm (P = .836). The following variables were independently associated with weight gain in all participants: baseline CD4 count, baseline human immunodeficiency virus type 1 (HIV-1) RNA, and CYP2B6 metaboliser genotype., Conclusions: CYP2B6 metaboliser genotype was associated with weight gain in PLWH starting efavirenz-based ART. Weight gain was similar between CYP2B6 extensive metabolizers in the efavirenz arm and in the dolutegravir arm, suggesting that impaired weight gain among CYP2B6 slow or intermediate metabolizers could explain the increased weight gain on dolutegravir compared with efavirenz observed in ADVANCE and other studies., (© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America.)

Background: Unwanted weight gain affects some people living with human immunodeficiency virus (HIV) who are prescribed integrase strand transfer inhibitors (INSTIs). Mechanisms and risk factors are incompletely understood., Methods: We utilized 2 cohorts to study pharmacogenetics of weight gain following switch from efavirenz- to INSTI-based regimens. In an observational cohort, we studied weight gain at 48 weeks following switch from efavirenz- to INSTI-based regimens among patients who had been virologically suppressed for at least 2 years at a clinic in the United States. Associations were characterized with CYP2B6 and UGT1A1 genotypes that affect efavirenz and INSTI metabolism, respectively. In a clinical trials cohort, we studied weight gain at 48 weeks among treatment-naive participants who were randomized to receive efavirenz-containing regimens in AIDS Clinical Trials Group studies A5095, A5142, and A5202 and did not receive INSTIs., Results: In the observational cohort (n = 61), CYP2B6 slow metabolizers had greater weight gain after switch (P = .01). This was seen following switch to elvitegravir or raltegravir, but not dolutegravir. UGT1A1 genotype was not associated with weight gain. In the clinical trials cohort (n = 462), CYP2B6 slow metabolizers had lesser weight gain at week 48 among participants receiving efavirenz with tenofovir disoproxil fumarate (P = .001), but not those receiving efavirenz with abacavir (P = .65). Findings were consistent when stratified by race/ethnicity and by sex., Conclusions: Among patients who switched from efavirenz- to INSTI-based therapy, CYP2B6 genotype was associated with weight gain, possibly reflecting withdrawal of the inhibitory effect of higher efavirenz concentrations on weight gain. The difference by concomitant nucleoside analogue is unexplained., (© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

In an analysis of randomized trials, use of efavirenz for treatment of human immunodeficiency virus (HIV) infection was associated with increased suicidal thoughts/behaviors. However, analyses of observational data have found no evidence of increased risk. To assess whether population differences might explain this divergence, we transported the effect of efavirenz use from these trials to a specific target population. Using inverse odds weights and multiple imputation, we transported the effect of efavirenz on suicidal thoughts/behaviors in these randomized trials (participants were enrolled in 2001-2007) to a trials-eligible cohort of US adults initiating antiretroviral therapy while receiving HIV clinical care at medical centers between 1999 and 2015. Overall, 8,291 cohort participants and 3,949 trial participants were eligible. Prescription of antidepressants (19% vs. 13%) and injection drug history (16% vs. 10%) were more frequent in the cohort than in the trial participants. Compared with the effect in trials, the estimated hazard ratio for efavirenz on suicidal thoughts/behaviors was attenuated in our target population (trials: hazard ratio (HR) = 2.3 (95% confidence interval (CI): 1.2, 4.4); transported: HR = 1.8 (95% CI: 0.9, 4.4)), whereas the incidence rate difference was similar (trials: HR = 5.1 (95% CI: 1.6, 8.7); transported: HR = 5.4 (95% CI: -0.4, 11.4)). In our target population, there was greater than 20% attenuation of the hazard ratio estimate as compared with the trials-only estimate. Transporting results from trials to a target population is informative for addressing external validity., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Severe hepatotoxicity in people with human immunodeficiency virus (HIV) receiving efavirenz (EFV) has been reported. We assessed the incidence and risk factors of hepatotoxicity in women of childbearing age initiating EFV-containing regimens., Methods: In the Promoting Maternal and Infant Survival Everywhere (PROMISE) trial, ART-naive pregnant women with HIV and CD4 count ≥ 350 cells/μL and alanine aminotransferase ≤ 2.5 the upper limit of normal were randomized during the antepartum and postpartum periods to antiretroviral therapy (ART) strategies to assess HIV vertical transmission, safety, and maternal disease progression. Hepatotoxicity was defined per the Division of AIDS Toxicity Tables. Cox proportional hazards models were constructed with covariates including participant characteristics, ART regimens, and timing of EFV initiation., Results: Among 3576 women, 2435 (68%) initiated EFV at a median 121.1 weeks post delivery. After EFV initiation, 2.5% (61/2435) had severe (grade 3 or higher) hepatotoxicity with an incidence of 2.3 (95% confidence interval [CI], 2.0-2.6) per 100 person-years. Events occurred between 1 and 132 weeks postpartum. Of those with severe hepatotoxicity, 8.2% (5/61) were symptomatic, and 3.3% (2/61) of those with severe hepatotoxicity died from EFV-related hepatotoxicity, 1 of whom was symptomatic. The incidence of liver-related mortality was 0.07 (95% CI, .06-.08) per 100 person-years. In multivariable analysis, older age was associated with severe hepatotoxicity (adjusted hazard ratio per 5 years, 1.35 [95% CI, 1.06-1.70])., Conclusions: Severe hepatotoxicity after EFV initiation occurred in 2.5% of women and liver-related mortality occurred in 3% of those with severe hepatotoxicity. The occurrence of fatal events underscores the need for safer treatments for women of childbearing age., (© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Objectives: Neuropsychiatric adverse effects (NPAE) related to efavirenz, mainly dizziness, is detrimental to human immunodeficiency virus (HIV) treatment. Our study aims at evaluating if zidovudine use potentiates the risk of dizziness related to efavirenz when used together and whether there are significant differences in over time distribution of this NPAE and others relatively frequents regarding efavirenz regimen without zidovudine., Methods: Human immunodeficiency virus-infected patients under efavirenz-containing different therapy were enrolled. A retrospective analysis of official medical records was accomplished to collect clinical data regarding NPAE occurrence and severity. Univariate statistic and statistical model based on survival analyses were performed., Key Findings: One hundred sixty-two patients were included, of these seventy-seven (47.5%) had NPAE reported, such as dizziness (more frequent), depression and insomnia. Univariate statistical analysis demonstrated that the combined use of efavirenz with zidovudine increased the NPAE risk (OR: 2.5; P-value: 0.008), mainly dizziness risk (OR: 3.5; P-value: 0.009) and survival analysis showed that such combination is associated with dizziness occurrence faster (HR: 2.9; P-value: 0.02)., Conclusions: The results may contribute to clarify the dizziness occurrence dynamics in therapy with efavirenz and zidovudine by identifying susceptibilities and assisting in the choice of combined antiretroviral therapy., (© 2020 Royal Pharmaceutical Society.)

Background: Efavirenz-related nervous system or psychiatric adverse drug reactions (ADRs) are conventionally reported to resolve soon after initiation, with incidence of dizziness at 8.5% in large clinical trials. Patients of black ethnicity are genetically at greater risk of elevated efavirenz exposure, which has been linked to nervous system toxicity., Patients and Methods: The current data derive from a prospective longitudinal observational study of adult HIV-positive outpatients taking current antiretrovirals, at three diverse clinics in central Uganda. As part of an interview about medicine use, patients were asked by trained pharmacy technicians to detail current side effects and to rate their severity on a simple visual analogue scale (1-10). Details of the reported ADRs were verified by case note review. Severity and causality of ADRs were rated by the study team using validated tools., Results: A total of 300 patients taking efavirenz were analysed. Of these, 108 (36%, 95% CI 30.6%-41.7%) were affected by persisting nervous system/psychiatric ADRs (median duration 22 months). Dizziness affected 27.3% (95% CI 22.4%-32.8%) of patients taking efavirenz. Severity of the ADRs was rated by patients at ≥5/10 in 76 (58.5%) cases. In 95 (86%) cases, there was no record of the ADRs in the clinical notes., Conclusions: Strategies are needed to identify and prioritize patients urgently with persisting efavirenz neurotoxicity for a switch to newer regimens as they become available.

Objectives: There are limited data regarding efavirenz pharmacogenetics in admixed populations. The Brazilian population is highly admixed. In a Brazilian cohort, we sought to characterize associations between efavirenz adverse effects (all-cause and CNS) and polymorphisms in seven genes known or suspected to affect efavirenz metabolism and transport., Methods: We studied 225 HIV-positive individuals who had been prescribed efavirenz-containing regimens at a hospital in Rio de Janeiro, Brazil. Eighty-nine cases had efavirenz adverse effects, including 43 with CNS adverse effects, while 136 controls had no adverse effect of any antiretroviral after treatment for at least 6 months. A total of 67 candidate polymorphisms in ABCB1, CYP2A6, CYP2B6, CYP3A4, CYP3A5, NR1I2 and NR1I3 genes were selected for association analysis. Admixture was assessed using 28 ancestry-informative polymorphisms previously validated for the Brazilian population. Associations were evaluated with logistic regression models adjusted for sex and genetic ancestry., Results: There was extensive African, European and Native American admixture in the cohort. Increased all-cause adverse effects were associated with the CYP2B6 genotype combination 15582CC-516TT-983TT (OR = 7.26, P = 0.003) and with the CYP2B6 slow metabolizer group 516TT or 516GT-983CT (OR = 3.10, P = 0.04). CNS adverse effects were nominally associated with CYP3A4 rs4646437 (OR = 4.63, P = 0.014), but not after adjusting for multiple comparisons., Conclusions: In a highly admixed Brazilian cohort, the CYP2B6 slow metabolizer genotype was associated with an increased risk of efavirenz adverse effects.

Among human immunodeficiency virus-positive women in Botswana on the recommended first-line antiretroviral therapy regimen, tenofovir-emtricitabine-efavirenz, initiated within the first or early second trimester, we found no increased risk of stillbirth, neonatal death, preterm/very preterm delivery, or the infant being born small or very small for gestational age. Treatment with tenofovir-emtricitabine-efavirenz <1 year before conception increased the risk of preterm delivery slightly over late-second-trimester treatment initiation (adjusted risk ratio, 1.33 [95% confidence interval, 1.04-1.70]).

Background: Randomized trials have shown increased risk of suicidality associated with efavirenz (EFV). The START (Strategic Timing of Antiretroviral Treatment) trial randomized treatment-naive human immunodeficiency virus (HIV)-positive adults with high CD4 cell counts to immediate vs deferred antiretroviral therapy (ART)., Methods: The initial ART regimen was selected prior to randomization (prespecified). We compared the incidence of suicidal and self-injurious behaviours (suicidal behavior) between the immediate vs deferred ART groups using proportional hazards models, separately for those with EFV and other prespecified regimens, by intention to treat, and after censoring participants in the deferred arm at ART initiation., Results: Of 4684 participants, 271 (5.8%) had a prior psychiatric diagnosis. EFV was prespecified for 3515 participants (75%), less often in those with psychiatric diagnoses (40%) than without (77%). While the overall intention-to-treat comparison showed no difference in suicidal behavior between arms (hazard ratio [HR], 1.07, P = .81), subgroup analyses suggest that initiation of EFV, but not other ART, is associated with increased risk of suicidal behavior. When censoring follow-up at ART initiation in the deferred group, the immediate vs deferred HR among those who were prespecified EFV was 3.31 (P = .03) and 1.04 (P = .93) among those with other prespecified ART; (P = .07 for interaction). In the immediate group, the risk was higher among those with prior psychiatric diagnoses, regardless of prespecified treatment group., Conclusions: Participants who used EFV in the immediate ART group had increased risk of suicidal behavior compared with ART-naive controls. Those with prior psychiatric diagnoses were at higher risk.

Background: Combination antiretroviral therapy (cART) use in pregnancy has been associated with hormonal dysregulation. We performed a secondary retrospective analysis of longitudinal progesterone and estradiol levels in pregnancy using specimens from the Protease Inhibitors to Reduce Malaria Morbidity in HIV-infected Pregnant Women study, which randomized Ugandan human immunodeficiency virus (HIV)-infected ART-naive women to initiate either lopinavir/ritonavir (LPV/r)-based or efavirenz (EFV)-based cART., Methods: Three hundred twenty-six women (160 randomized to the EFV arm and 166 women to the LPV/r arm) with at least 1 plasma sample collected during pregnancy were included. Enrollment samples collected prior to cART initiation were used as a cART-naive comparator group. Hormone levels were quantified by enzyme-linked immunosorbent assay., Results: Estradiol levels were differentially affected by the 2 cART regimens. Exposure to LPV/r was associated with an increase in estradiol (P < .0001), whereas exposure to EFV was associated with a decrease in estradiol (P < .0001), relative to the cART-naive gestationally matched comparator group. Lower estradiol levels correlated with small for gestational age (SGA) (P = .0019) and low birth weight (P = .019) in the EFV arm, while higher estradiol levels correlated with SGA in the LPV/r arm (P = .027). Although progesterone levels were similar between treatment arms, we observed an association between SGA and lower progesterone in the LPV/r arm (P = .04). No association was observed between hormone levels and preterm birth in either arm. Levels of progesterone and estradiol were lower in cases of stillbirth, and levels of both hormones declined immediately prior to stillbirth in 5 of 8 cases., Conclusions: Combination ART regimens differentially affect estradiol levels in pregnancy, a hormone critical to the maintenance of a healthy pregnancy. Identifying cART regimens that minimize perinatal HIV transmission without contributing to hormonal dysregulation represents an urgent public health priority., Clinical Trials Registration: NCT00993031., (© The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Background: Antiretroviral drugs with a lower potential to induce hepatic steatosis in human immunodeficiency virus (HIV) infection need to be identified. We compared the effect of switching efavirenz (EFV) to raltegravir (RAL) on hepatic steatosis among HIV-infected patients with nonalcoholic fatty liver disease (NAFLD) receiving EFV plus 2 nucleoside analogues., Methods: HIV-infected patients on EFV plus tenofovir/emtricitabine or abacavir/lamivudine with NAFLD were randomized 1:1 to switch from EFV to RAL (400 mg twice daily), maintaining nucleoside analogues unchanged, or to continue with EFV plus 2 nucleoside analogues. At baseline, eligible patients should show controlled attenuation parameter (CAP) values ≥238 dB/m. Changes in hepatic steatosis at 48 weeks of follow-up over baseline levels were measured by CAP., Results: Overall, 39 patients were included, and 19 of them were randomized to switch to RAL. At week 48, median CAP for the RAL group was 250 (Q1-Q3, 221-277) dB/m and 286 (Q1-Q3, 269-314) dB/m for the EFV group (P = .035). The median decrease in CAP values was -20 (Q1-Q3, -67 to 15) dB/m for the RAL arm and 30 (Q1-Q3, -17 to 49) dB/m for the EFV group (P = .011). CAP values <238 dB/m at week 48 were observed in 9 (47%) patients on RAL and 3 (15%) individuals on EFV (P = .029)., Conclusions: After 48 weeks, HIV-infected individuals switching EFV to RAL showed decreases in the degree of hepatic steatosis, as measured by CAP, compared with those continuing with EFV. In addition, the proportion of patients without significant hepatic steatosis after 48 weeks was greater for those who switched to RAL., Clinical Trials Registration: NCT01900015., (© The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Background: We examined associations between suicidality and genotypes that predict plasma efavirenz exposure among AIDS Clinical Trials Group study participants in the United States., Methods: Four clinical trials randomly assigned treatment-naive participants to efavirenz-containing regimens; suicidality was defined as reported suicidal ideation or attempted or completed suicide. Genotypes that predict plasma efavirenz exposure were defined by CYP2B6 and CYP2A6 polymorphisms. Associations were evaluated with weighted Cox proportional hazards models stratified by race/ethnicity. Additional analyses adjusted for genetic ancestry and selected covariates., Results: Among 1833 participants, suicidality was documented in 41 in exposed analyses, and 34 in on-treatment analyses. In unadjusted analyses based on 12 genotype levels, suicidality increased per level in exposed (hazard ratio, 1.11; 95% confidence interval, .96-1.27) and on-treatment 1.16; 1.01-1.34) analyses. In the on-treatment analysis, the association was strongest among white but nearly null among black participants. Considering 3 metabolizer levels (extensive, intermediate and slow), slow metabolizers were at increased risk. Results were similar after baseline covariate-adjustment for genetic ancestry, sex, age, weight, injection drug use history, and psychiatric history or recent psychoactive medication., Conclusions: Genotypes that predict higher plasma efavirenz exposure were associated with increased risk of suicidality. Strength of association varied by race/ethnicity., (© The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.)

Background.: The long-term effectiveness of human immunodeficiency virus (HIV) treatments containing integrase inhibitors is unknown., Methods.: We use observational data from the Centers for AIDS Research Network of Integrated Clinical Systems and the Centers for Disease Control and Prevention to estimate 4-year risk of AIDS and all-cause mortality among 415 patients starting a raltegravir regimen compared to 2646 starting an efavirenz regimen (both regimens include emtricitabine and tenofovir disoproxil fumarate). We account for confounding and selection bias as well as generalizability by standardization for measured variables, and present both observational intent-to-treat and per-protocol estimates., Results.: At treatment initiation, 12% of patients were female, 36% black, 13% Hispanic; median age was 37 years, CD4 count 321 cells/µL, and viral load 4.5 log10 copies/mL. Two hundred thirty-five patients incurred an AIDS-defining illness or died, and 741 patients left follow-up. After accounting for measured differences, the 4-year risk was similar among those starting both regimens (ie, intent-to treat hazard ratio [HR], 0.96 [95% confidence interval {CI}, .63-1.45]; risk difference, -0.9 [95% CI, -4.5 to 2.7]), as well as among those remaining on regimens (ie, per-protocol HR, 0.95 [95% CI, .59-1.54]; risk difference, -0.5 [95% CI, -3.8 to 2.9])., Conclusions.: Raltegravir and efavirenz-based initial antiretroviral therapy have similar 4-year clinical effects. Vigilance regarding longer-term comparative effectiveness of HIV regimens using observational data is needed because large-scale experimental data are not forthcoming., (© The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Background: We investigated changes in hepatic fibrosis, based on transient elastography (TE), among human immunodeficiency virus (HIV)-infected patients with and without hepatitis B virus (HBV) coinfection on antiretroviral therapy (ART) in Zambia., Methods: Patients' liver stiffness measurements (LSM; kiloPascals [kPa]) at ART initiation were categorized as no or minimal fibrosis (equivalent to Metavir F0-F1), significant fibrosis (F2-F3), and cirrhosis (F4). TE was repeated following 1 year of ART. Stratified by HBV coinfection status (hepatitis B surface antigen positive at baseline), we described LSM change and the proportion with an increase/decrease in fibrosis category. Using multivariable logistic regression, we assessed correlates of significant fibrosis/cirrhosis at 1 year on ART., Results: Among 463 patients analyzed (61 with HBV coinfection), median age was 35 years, 53.7% were women, and median baseline CD4+ count was 240 cells/mm3. Nearly all (97.6%) patients received tenofovir disoproxil fumarate-containing ART, in line with nationally recommended first-line treatment. The median LSM change was -0.70 kPa (95% confidence interval, -3.0 to +1.7) and was similar with and without HBV coinfection. Significant fibrosis/cirrhosis decreased in frequency from 14.0% to 6.7% (P < .001). Increased age, male sex, and HBV coinfection predicted significant fibrosis/cirrhosis at 1 year (all P < .05)., Conclusion: The percentage of HIV-infected Zambian adults with elevated liver stiffness suggestive of significant fibrosis/cirrhosis decreased following ART initiation-regardless of HBV status. This suggests that HIV infection plays a role in liver inflammation. HBV-coinfected patients were more likely to have significant fibrosis/cirrhosis at 1 year on ART., Clinical Trials Registration: NCT02060162., (© The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Background: Child-friendly, low-cost, solid, oral fixed-dose combinations (FDCs) of efavirenz with lamivudine and abacavir are urgently needed to improve clinical management and drug adherence for children., Methods: Data were pooled from several clinical trials and therapeutic drug monitoring datasets from different countries. The number of children/observations was 505/3667 for efavirenz. Population pharmacokinetic analyses were performed using a non-linear mixed-effects approach. For abacavir and lamivudine, data from 187 and 920 subjects were available (population pharmacokinetic models previously published). Efavirenz/lamivudine/abacavir FDC strength options assessed were (I) 150/75/150, (II) 120/60/120 and (III) 200/100/200 mg. Monte Carlo simulations of the different FDC strengths were performed to determine the optimal dose within each of the WHO weight bands based on drug efficacy/safety targets., Results: The probability of being within the target efavirenz concentration range 12 h post-dose (1-4 mg/L) varied between 56% and 60%, regardless of FDC option. Option I provided a best possible balance between efavirenz treatment failure and toxicity risks. For abacavir and lamivudine, simulations showed that for option I >75% of subjects were above the efficacy target., Conclusions: According to simulations, a paediatric efavirenz/lamivudine/abacavir fixed-dose formulation of 150 mg efavirenz, 75 mg lamivudine and 150 mg abacavir provided the most effective and safe concentrations across WHO weight bands, with the flexibility of dosage required across the paediatric population., (© The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

Background: The current study was conducted to determine if efavirenz (EFV) or atazanavir/ritonavir (ATV/r)-based combination antiretroviral therapy (cART) impacted steady-state atovaquone plasma concentrations in human immunodeficiency virus (HIV)-infected patients receiving treatment doses of atovaquone., Methods: Thirty HIV-infected volunteers were recruited, 10 taking no cART and 10 each taking cART that included EFV or ATV/r. Subjects were randomly assigned to atovaquone 750 mg twice daily (BID) for 14 days followed by atovaquone 1500 mg BID for 14 days, or vice-versa, with a washout period in between. On day 14 of each phase, blood was sampled for pharmacokinetic studies, and the area under the concentration-time curve (AUCτ) and average concentration (C avg) were calculated and compared using an unpaired t test., Results: Twenty-nine subjects completed both dosing cohorts. Subjects receiving EFV-based cART had 47% and 44% lower atovaquone AUCτ than subjects not receiving cART at atovaquone doses of 750 mg BID and 1500 mg BID, respectively (P≤ .01). Only 5 of 10 subjects receiving EFV-based cART plus atovaquone 750 mg BID had an atovaquone C avg>15 µg/mL, which has previously been associated with successful treatment of Pneumocystis jirovecipneumonia. AUCτ and Cavg did not significantly differ for concurrent ATV/r for 750 mg BID or 1500 mg BID when compared to the group not receiving cART. Nine of 10 subjects not receiving cART, 8 of 10 subjects receiving ATV/r, and 2 of 10 subjects receiving EFV in combination with atovaquone 750 mg BID achieved an atovaquone C avg>18.5 µg/mL, a concentration that has previously been associated with successful treatment of Toxoplasmaencephalitis (TE)., Conclusions: These data suggest that the currently recommended dose of atovaquone 750 mg BID for treatment of mild to moderate PCP may not be adequate in patients receiving concurrent EFV. Furthermore, doses lower than the currently recommended dose of 1500 mg BID may achieve plasma concentrations adequate to treat TE in HIV-infected patients not receiving EFV., Clinical Trials Registration: NCT01479361., (Published by Oxford University Press for the Infectious Diseases Society of America 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.)

The NNRTI efavirenz has long been one of the most frequently employed antiretroviral drugs in the multidrug regimens used to treat HIV infection, in accordance with its well-demonstrated antiretroviral efficacy and favourable pharmacokinetics. However, growing concern about its adverse effects has sometimes led to efavirenz being replaced by other drugs in the initial treatment selection or to switching of therapy to efavirenz-free regimens in experienced patients. Neurological and neuropsychiatric reactions are the manifestations most frequently experienced by efavirenz-treated patients and range from transitory effects, such as nightmares, dizziness, insomnia, nervousness and lack of concentration, to more severe symptoms including depression, suicidal ideation or even psychosis. In addition, efavirenz has recently been associated with mild/moderate neurocognitive impairment, which is of specific relevance given that half of the patients receiving ART eventually suffer some form of HIV-associated neurocognitive disorder. The mechanisms responsible for efavirenz-induced neurotoxicity are unclear, although growing evidence points to disturbances in brain mitochondrial function and bioenergetics. This review offers a comprehensive overview of the current evidence on the interaction that efavirenz displays with the CNS, including the penetration and concentration of the drug in the brain. We discuss the prevalence, types and specificities of its side effects and recently uncovered cellular mechanisms that may be involved in their development., (© The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

Objectives: The HIV NNRTI rilpivirine is being evaluated as a possible agent for HIV pre-exposure prophylaxis. We have recently shown that the NNRTI efavirenz may impair endothelial function assessed as flow-mediated dilation (FMD), but whether this impairment is also found with rilpivirine is unknown. We sought to compare cardiovascular risk profiles between efavirenz and rilpivirine in healthy volunteers., Methods: We performed a prospective, randomized, open-label trial in 40 HIV-uninfected healthy volunteers who were randomized 1: 1 to either efavirenz or rilpivirine. Vascular indices, metabolic parameters, inflammatory biomarkers and oxidative stress were measured before and after 4 weeks of treatment. This study is registered at ClinicalTrials.gov (NCT01585038)., Results: There were no significant differences in 4 week mean (SD) changes in FMD between efavirenz and rilpivirine [0.089 (3.65)% versus 0.63 (2.42)%; P = 0.77]. There were also no significant differences in 4 week changes in high-sensitivity C-reactive protein, IL-6, soluble vascular cell adhesion molecule-1, HDL-cholesterol, triglycerides or homeostasis model assessment-insulin resistance. However, efavirenz led to significant increases in total cholesterol [19.39 (23.9) versus -5.78 (16.5) mg/dL; P < 0.001], LDL-cholesterol [13.29 (19.5) versus -2.24 (13.4) mg/dL; P = 0.009] and F2-isoprostanes [92.7 (178.6) versus -101.4 (215.7) pg/mL; P = 0.019] compared with rilpivirine. Two participants from each study group discontinued prematurely for adverse events., Conclusions: There were no significant differences in the changes in endothelial function over 1 month between the efavirenz and rilpivirine groups, although efavirenz had worse lipid changes compared with rilpivirine. Longer-term studies are required for confirmation., (© The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

Study Question: Are antiretroviral therapies associated with semen alterations in HIV-infected men?, Summary Answer: Antiretroviral regimens that included the non-nucleosidic reverse transcriptase inhibitor efavirenz were associated with a significant impairment of sperm motility, whereas regimens without efavirenz were not associated with significant semen changes., What Is Known Already: Semen alterations including decreased ejaculate volume and sperm motility have been reported in HIV-infected men. The hypothesis ascribing reduced sperm motility to damages induced in sperm mitochondria by nucleosidic (or nucleotidic) reverse transcriptase inhibitors (NRTIs) has not been confirmed in HIV-infected patients and the effects of antiretroviral treatments on semen parameters remain unclear., Study Design, Size, Duration: This case-control study compared semen characteristics across 378 HIV-1 infected patients receiving different antiretroviral regimens or never treated by antiretroviral drugs, in whom an initial semen analysis was done between 2001 and 2007., Participants/materials, Setting, Methods: The patients were partners from serodiscordant couples requesting medical assistance to procreate safely. Their status with regard to antiretroviral therapy at the time of semen analysis was categorized as follows: 1/ never treated patients (n = 66); 2/ patients receiving NRTIs only (n = 49); 3/ patients receiving a NRTIs + protease inhibitor (PI) regimen (n = 144); 4/ patients receiving a NRTIs + non-nucleosidic reverse transcriptase inhibitor (NNRTI) regimen (n = 119). Semen parameters were assessed through standard semen analysis. Additional analyses included measurement of sperm motion parameters using computer-assisted semen analysis, seminal bacteriological analysis, seminal biochemical markers and testosterone plasmatic levels. All analyses were performed in the Cochin academic hospital. The data were analyzed through multivariate analysis., Main Results and the Role of Chance: Sperm motility was the only semen parameter which significantly varied according to treatment status. The median percentage of rapid spermatozoa was 5% in the group of patients receiving a regimen including efavirenz versus 20% in the other groups (P < 0.0001). Accordingly, sperm velocity was reduced by about 30% in this group (P < 0.0001). The role of chance was minimized by the strict definition and the size of the study population, which included a large enough group of never treated patients, the controlled conditions of semen collection and analysis, the multivariate analysis, the specificity and the high significance level of the observed differences., Limitations, Reasons for Caution: The design of the study did not allow demonstrating a causal link between exposure to efavirenz and sperm motility., Wider Implications of the Findings: As efavirenz is widely used in current antiretroviral therapy, these findings may concern many HIV-infected men wishing to have children. This justifies further assessment of the consequences on fertility of the exposure to efavirenz. Moreover, the possibility of common cellular impacts underlying adverse effects of efavirenz in sperm cells and neurons deserved investigation., Study Funding/competing Interests: No external funding was used for this study. None of the authors has any conflict of interest to declare., (© The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Background: Neurological pathogenesis is associated with mitochondrial dysfunction and differences in neuronal/glial handling of oxygen and glucose. The main side effects attributed to efavirenz involve the CNS, but the underlying mechanisms are unclear., Methods: Human cell lines and rat primary cultures of neurons and astrocytes were treated with clinically relevant efavirenz concentration., Results: Efavirenz alters mitochondrial respiration, enhances reactive oxygen species generation, undermines mitochondrial membrane potential, and reduces adenosine triphosphate (ATP) levels in a concentration-dependent fashion in both neurons and glial cells. However, it activates adenosine monophosphate-activated protein kinase only in glial cells, upregulating glycolysis and increasing intracellular ATP levels, which do not occur in neurons. To reproduce the conditions that often exist in human immunodeficiency virus-related neuroinflammatory disorders, the effects of efavirenz were evaluated in the presence of exogenous nitric oxide, an inflammatory mediator and mitochondrial inhibitor. The combination potentiated the effects on mitochondrial parameters in both neurons and glial cells, but ATP generation and lactate production were enhanced only in glial cells., Conclusions: Efavirenz affects the bioenergetics of neurons through a mechanism involving acute mitochondrial inhibition, an action exacerbated in neuroinflammatory conditions. A similar scenario of glial cells survival and degeneration of neurons with signs of mitochondrial dysfunction and oxidative stress has been associated with neurocognitive disorders., (© The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

Efavirenz has been recommended as a preferred third agent together with two nucleos(t)ides for first-line combination antiretroviral therapy (ART) for >15 years. The availability of efavirenz in a fixed-dose combination makes it very attractive. However, because of (i) adverse events associated with efavirenz, (ii) a poorer overall efficacy of efavirenz compared with newer antiretrovirals, (iii) the ranking of efavirenz as FDA Pregnancy Category D and (iv) the relatively high prevalence of transmitted drug-resistance mutations, there is a need to reconsider the role of efavirenz in first-line ART. We review the available evidence that challenges efavirenz's current position in first-line HIV treatment guidelines. Apart from its animal teratogenic potential, and moderate neuropsychiatric adverse events associated with its use, efavirenz has recently been associated with an increased risk of suicidality when compared with other antiretroviral drugs. Most importantly, efavirenz has demonstrated overall inferior efficacy to various comparator drugs, which include rilpivirine, raltegravir and dolutegravir, in antiretroviral-naive patients. Furthermore, epidemiological data indicate that the prevalence of non-nucleoside reverse transcriptase inhibitor resistance has reached 5%-8% in various parts of the world, and minority transmitted non-nucleoside reverse transcriptase inhibitor resistance-associated mutations can have a negative impact on the outcome of first-line efavirenz-based ART. Based on considerations of efficacy, toxicity and resistance, it is time to reconsider the routine use of efavirenz in ART. This, of course, presupposes that other antiretrovirals will be available in place of efavirenz, and may not be applicable in certain developing country settings where this is not the case., (© The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

Objectives: Information on the long-term effectiveness and tolerability of efavirenz- or nevirapine-based antiretroviral therapy (ART) in Africa is lacking. The primary objective of this retrospective observational study was to compare the long-term clinical and immunological outcomes of efavirenz- versus nevirapine-based first-line ART in a large government clinic in Ghana., Patients and Methods: The main outcomes were AIDS, death, ART-related toxicity, discontinuation of ART and a composite endpoint of death, AIDS or ART discontinuation. These time-to-event outcomes were compared using a Cox proportional hazards regression model. CD4 counts on ART were compared using a mixed-effects model., Results: A total of 3990 patients started non-nucleoside reverse transcriptase inhibitor (NNRTI)-based ART between 2004 and 2010, of which 2369 (59%) were on efavirenz. No significant differences were apparent between each NNRTI for subsequent risk of AIDS, death or the composite of treatment failure; however, stavudine use was independently associated with an increased risk of death [adjusted hazard ratio (HR) 1.60 (95% CI: 1.21-2.11)]. There was an increased risk of early toxicity with nevirapine leading to discontinuation [adjusted HR 1.53 (95% CI: 1.23-1.97)], mostly due to excess skin rashes in the first 2 months of treatment; however, overall discontinuation rates were low., Conclusions: There was no difference in the long-term effectiveness of efavirenz- and nevirapine-based ART in this population; however, patients initiating nevirapine were more likely to develop early toxicity and discontinue this drug. The excess mortality observed in patients taking stavudine is of concern and should prompt increased efforts to replace it with alternative antiretroviral drugs in developing countries.

Objectives: In HIV-infected persons, a rash is the most common manifestation of drug hypersensitivity reactions. Non-nucleotide reverse transcriptase inhibitors are a major cause of cutaneous reactions. While the characteristics of nevirapine-associated cutaneous adverse drug reactions (CADRs) have been well described, there are limited data on efavirenz-associated CADRs. The objective of this study was to characterize the clinical features of consecutive cases of efavirenz-associated CADRs in a single referral centre diagnosed over a 3 year period., Methods: We retrospectively reviewed the clinical records of 231 patients admitted with CADRs to a tertiary dermatology ward in Cape Town, South Africa., Results: In 42/231(18%) cases, there had been exposure to efavirenz in the preceding 8 weeks. Of these, 5/42 (12%) patients were diagnosed with probable efavirenz-associated CADRs based on the Naranjo score. The median exposure to efavirenz before the onset of the rash was 12 days (range 2-48). All the patients were female, with a median age of 31 years and a median CD4 cell count of 300 cells/mm(3) (range 81-887). Four had a photo-distributed eruption and one had a confluent indurated erythema affecting the face, trunk and limbs. In three out of five cases, there were annular plaques with raised erythematous edges and dusky centres, which were photo-distributed. Two patients had a mild transaminitis and another a mild eosinophilia. Histological features were non-specific, with perivascular lymphocytes the only consistent feature. In all five cases, efavirenz was withdrawn and potent topical steroid was the only CADR-specific intervention. The eruptions resolved on discharge from hospital, with no sequelae except for residual post-inflammatory hyperpigmentation., Conclusions: Photo-distribution and annular erythema should alert clinicians to the possibility of efavirenz-associated CADRs.

Introduction: Current WHO guidelines for developing countries recommend efavirenz (EFV) and nevirapine (NVP) for first-line antiretroviral treatment (ART). This paper compares the effectiveness of EFV and NVP among ART-naive patients initiating treatment at 56 public health facilities in South Africa between January 2004 and December 2007., Methods: Participants were assigned to the EFV or NVP cohorts depending on their baseline ART regimen. Mortality, viral load suppression after 6 months and ART regimen change were compared between the cohorts using Cox proportional hazards models and logistic regression., Results: At initiation, 19 441 (71.1%) patients started EFV and 7909 (28.9%) started NVP treatment. The median follow-up period was 9.5 months (IQR 4.6-17.7). After adjustment, mortality was similar in the two cohorts, (adjusted HR = 1.07, 95% CI 0.89-1.28). Viral load suppression at 6 months was higher in the EFV cohort overall (adjusted odds ratio [AOR] = 1.29, 95% CI 1.05-1.59) and in women aged 16-40 years (AOR = 1.35, 95% CI 1.11-1.63) and women with CD4 counts <25 cells/µL (AOR = 1.95, 95% CI 1.01-3.76). Patients starting on EFV were 47% less likely to change regimen (AOR = 0.53, 95% CI 0.48-0.59)., Discussion: These findings suggest the superior effectiveness of EFV for first-line ART compared with NVP and should be considered during development of future ART guidelines for high-burden regions.

Objectives: The aim of this study was to assess 25-hydroxyvitamin D (vitamin D) status in an HIV-infected adult population and to define HIV- and antiretroviral-related factors associated with vitamin D deficiency., Methods: Using data from a prospective cohort of HIV-infected adult patients followed in five French centres (Dat'AIDS cohort), we evaluated the prevalence of vitamin D deficiency/insufficiency (<30 ng/mL). A multiple linear regression model was used to examine risk factors for vitamin D deficiency (≤10 ng/mL)., Results: Vitamin D deficiency/insufficiency was observed in 86.7% of the 2994 patients, including 55.6% with vitamin D insufficiency and 31.1% with vitamin D deficiency. In multivariate analysis, factors associated with vitamin D deficiency were current smoking [adjusted OR (aOR) 1.55], estimated glomerular filtration rate ≥90 mL/min/1.73 m(2) (aOR 1.51), vitamin D measurement not performed in summer (aOR 0.27), CD4 <350 cells/mm(3) (aOR 1.37 for CD4 200 to <350 and 1.62 for CD4 <200 cells/mm(3)) and antiretroviral therapy (aOR 2.61). Gender, body mass index, age, coinfection and previous AIDS were not associated factors. In the antiretroviral-treated population (n = 2660), besides the same factors found in the whole population, efavirenz was the only drug to be significantly associated with deficiency, with an aOR of 1.89 (95% CI 1.45-2.47)., Conclusions: Vitamin D deficiency is frequent in this HIV-infected population. Patients on antiretroviral therapy are at higher risk of vitamin D deficiency than antiretroviral-naive patients, with an increased risk in patients receiving efavirenz. No effect of the other antiretrovirals, including the latest (etravirine, darunavir, raltegravir), was found.

Objectives: The efficacy and hepatic safety of the non-nucleoside reverse transcriptase inhibitors rilpivirine (TMC278) and efavirenz were compared in treatment-naive, HIV-infected adults with concurrent hepatitis B virus (HBV) and/or hepatitis C virus (HCV) infection in the pooled week 48 analysis of the Phase III, double-blind, randomized ECHO (NCT00540449) and THRIVE (NCT00543725) trials., Methods: Patients received 25 mg of rilpivirine once daily or 600 mg of efavirenz once daily, plus two nucleoside/nucleotide reverse transcriptase inhibitors. At screening, patients had alanine aminotransferase/aspartate aminotransferase levels ≤5× the upper limit of normal. HBV and HCV status was determined at baseline by HBV surface antigen, HCV antibody and HCV RNA testing., Results: HBV/HCV coinfection status was known for 670 patients in the rilpivirine group and 665 in the efavirenz group. At baseline, 49 rilpivirine and 63 efavirenz patients [112/1335 (8.4%)] were coinfected with either HBV [55/1357 (4.1%)] or HCV [57/1333 (4.3%)]. The safety analysis included all available data, including beyond week 48. Eight patients seroconverted during the study (rilpivirine: five; efavirenz: three). A higher proportion of patients achieved viral load <50 copies/mL (intent to treat, time to loss of virological response) in the subgroup without HBV/HCV coinfection (rilpivirine: 85.0%; efavirenz: 82.6%) than in the coinfected subgroup (rilpivirine: 73.5%; efavirenz: 79.4%) (rilpivirine, P = 0.04 and efavirenz, P = 0.49, Fisher's exact test). The incidence of hepatic adverse events (AEs) was low in both groups in the overall population (rilpivirine: 5.5% versus efavirenz: 6.6%) and was higher in HBV/HCV-coinfected patients than in those not coinfected (26.7% versus 4.1%, respectively)., Conclusions: Hepatic AEs were more common and response rates lower in HBV/HCV-coinfected patients treated with rilpivirine or efavirenz than in those who were not coinfected.

Background: Etravirine is approved for use in treatment-experienced patients at a dose of 200 mg twice daily. Efavirenz has been associated with greater increases in serum lipids compared with other non-nucleosides in randomized trials of first-line treatment., Methods: In this double-blind, placebo-controlled trial, 157 treatment-naive patients with HIV RNA >5000 copies/mL were randomized 1:1 to either 400 mg of etravirine once daily (n=79) or 600 mg of efavirenz once daily (n=78) plus two nucleoside analogues (either abacavir/lamivudine, zidovudine/lamivudine or tenofovir/emtricitabine) for 48 weeks. Lipids were measured under fasting conditions at baseline and all visits to Week 48. Clinicaltrials.gov identifier: NCT00903682., Results: Overall, the patients had a median baseline CD4 count of 302 cells/mm(3) (range 74-722) and a median HIV RNA of 4.8 log(10) copies/mL (range 3.5-6.6). Both the non-nucleosides and the nucleoside analogues used caused changes in serum lipids. In the efavirenz arm, patients showed significantly larger increases in high-density lipoprotein (HDL) (+0.15 mmol/L, P=0.004), low-density lipoprotein (LDL) (+0.35 mmol/L, P=0.005), total cholesterol (+0.61 mmol/L, P<0.0001) and triglycerides (+0.33 mmol/L, P=0.03) at Week 48 compared with the etravirine arm. Across the two arms, patients taking abacavir/lamivudine showed greater increases in total cholesterol (+0.47 mmol/L, P=0.005) compared with patients taking tenofovir/emtricitabine. There were fewer grade 3/4 elevations in total cholesterol, LDL and triglycerides in the etravirine arm (2 patients, 1 patient and 0 patients, respectively) versus the efavirenz arm (8 patients, 6 patients and 2 patients, respectively)., Conclusions: In the SENSE trial, first-line treatment with 400 mg of etravirine once daily plus two nucleoside analogues led to fewer grade 3 or 4 lipid elevations compared with efavirenz plus two nucleoside analogues.

Objectives: To compare the frequency of grade 3 or 4 transaminase elevations (TEs) in HIV/hepatitis C virus (HCV) co-infected patients who started a three-antiretroviral drug regimen including efavirenz or a ritonavir-boosted protease inhibitor (PI/r) and the influence of pre-existing significant hepatic fibrosis or cirrhosis., Patients and Methods: All pre-treated or treatment-naive HIV/HCV co-infected patients who started an antiretroviral regimen including two nucleos(t)ide reverse transcriptase inhibitors along with efavirenz or a PI/r in seven Spanish centres from January 2007 to December 2009 were included in this prospective study., Results: Of 262 patients included in this study, 76 (29%) individuals began antiretroviral therapy (ART) including efavirenz and 186 (71%) a PI/r-based combination. The median (interquartile) follow-up was 14.0 (6.2-23.7) months. A total of 20 (7.6%) patients presented grade 3-4 TEs. Four (1.5%) subjects discontinued ART due to this adverse event. Grade 3-4 TEs were observed in 5 (6.6%) subjects receiving efavirenz and 15 (8.1%) treated with PI/r (P = 0.681). Three (6.5%) patients in the efavirenz group with significant fibrosis developed grade 3-4 TEs versus 2 (8.7%) without pre-existing significant fibrosis (P = 0.743). In the PI/r group, the corresponding figures were 10 (8.8%) and 5 (9.3%), respectively (P = 0.931)., Conclusions: The frequency of grade 3-4 TEs associated with efavirenz-based ART combinations under clinical practice conditions is low and similar to that found in patients receiving PI/r currently used in HIV/HCV co-infected patients. The baseline fibrosis stage does not have an impact on the development of TEs caused by these antiretroviral drugs in this population.

Background: Efavirenz is among the most widely used antiretroviral drugs. Increased efavirenz exposure has been associated with CNS side effects and also with the chance of emergence of resistance upon treatment interruptions. The objective of this study was to evaluate factors associated with efavirenz plasma concentrations in a cohort of HIV-infected individuals., Methods: From July 2009 to March 2010, HIV-infected patients with efavirenz as part of antiretroviral therapy (600 mg at night), undetectable viral load for at least 1 year and CD4 cell count >200 cells/mm(3) were consecutively enrolled at the HIV/AIDS ambulatory care unit in southern Brazil. Plasma samples were taken 18-23 h after efavirenz last dose and analysed by validated ultra-performance liquid chromatography., Results: Forty-one subjects were included (21 females). Mean age and weight were 45.4 years and 70.9 kg, respectively. Mean efavirenz plasma concentration was 2.20 ± 2.17 mg/L. Most plasma concentrations (73%) were within the therapeutic window (1-4 mg/L); 17% were below and 10% above the limits. There were no significant associations between efavirenz concentration and age, CD4 cell count, time on antiretroviral treatment and gender. There was significant and inverse correlation between efavirenz concentrations and body weight (P = 0.013) and body mass index (P = 0.001)., Conclusions: In this cohort of well-controlled HIV-positive individuals, patients with lower weight or body mass index had a higher chance of presenting elevated plasma concentrations of efavirenz. Therapeutic drug monitoring to adjust dose might be a helpful tool to decrease efavirenz dose in order to minimize costs and adverse effects.

Background: Nevirapine (NVP) can be safely and effectively administered once-daily but has not been assessed in human immunodeficiency virus (HIV)-infected patients with tuberculosis (TB). We studied the safety and efficacy of once-daily NVP, compared with efavirenz (EFV; standard therapy); both drugs were administered in combination with 2 nucleoside reverse-transcriptase inhibitors., Methods: An open-label, noninferiority, randomized controlled clinical trial was conducted at 3 sites in southern India. HIV-infected patients with TB were treated with a standard short-course anti-TB regimen (2EHRZ(3)/4RH(3); [2 months of Ethambutol, Isoniazid, Rifampicin, Pyrazinamide / 4 months of Isoniazid and Rifampicin] thrice weekly) and randomized to receive once-daily EFV at a dose of 600 mg or NVP at a dose of 400 mg (after 14 days of 200 mg administered once daily) with didanosine 250/400 mg and lamivudine 300 mg after 2 months. Sputum smears and mycobacterial cultures were performed every month. CD4+ cell count, viral load, and liver function test results were monitored periodically. Primary outcome was a composite of death, virological failure, default, or serious adverse event (SAE) at 24 weeks. Both intent-to-treat and per protocol analyses were done, and planned interim analyses were performed., Results: A total of 116 patients (75% [87 patients] of whom had pulmonary TB), with a mean age of 36 years, a median CD4+ cell count of 84 cells/mm(3), and a median viral load of 310 000 copies/mL, were randomized. At 24 weeks, 50 of 59 patients in the EFV group and 37 of 57 patients in the NVP group had virological suppression (P = .024). There were no deaths, 1 SAE, and 5 treatment failures in the EFV arm, compared with 5 deaths, 2 SAEs, and 10 treatment failures in the NVP arm. The trial was halted by the data and safety monitoring board at the second interim analysis. Favorable TB treatment outcomes were observed in 93% of the patients in the EFV arm and 84% of the patients in the NVP arm (P = .058)., Conclusions: Compared with a regimen of didanosine, lamivudine, and EFV, a regimen of once-daily didanosine, lamivudine, and NVP was inferior and was associated with more frequent virologic failure and death. Clinical Trials Registration. NCT00332306.

Background: We compared 3 years of antiretroviral therapy with raltegravir or efavirenz as part of a combination regimen in the ongoing STARTMRK study of treatment-naive patients infected with human immunodeficiency virus (HIV)., Methods: Eligible patients with HIV-1 RNA (vRNA) levels >5000 copies/mL and without baseline resistance to efavirenz, tenofovir, or emtricitabine were randomized in a double-blind, noninferiority study to receive raltegravir or efavirenz, each combined with tenofovir/emtricitabine. Outcomes included viral suppression, adverse events, and changes from baseline metabolic parameters. Dual energy X-ray absorptiometry scans were obtained on a convenience sample of patients at prespecified time points to assess changes in body fat composition., Results: At week 156 counting noncompleters as failures, 212 (75.4%) of 281 versus 192 (68.1%) of 282 had vRNA levels <50 copies/mL in the raltegravir and efavirenz groups, respectively [Δ (95% CI) = 7.3% (-0.2, 14.7), noninferiority P < .001]. Mean changes from baseline CD4 count were 332 and 295 cells/mm³ in the raltegravir and efavirenz arms, respectively [Δ (95% CI) = 37 (4, 69)]. Consistent virologic and immunologic efficacy was maintained across prespecified demographic and baseline prognostic subgroups for both treatment groups. Fewer drug-related clinical adverse events (49% vs 80%; P < .001) occurred in raltegravir than efavirenz recipients, with discontinuations due to adverse events in 5% and 7%, respectively. Elevations in fasting lipid levels (including LDL- and HDL-cholesterol) were consistently lower in the raltegravir than efavirenz group (P < .005). Fat gain was 19% in 25 raltegravir recipients and 31% in 32 efavirenz recipients at week 156., Conclusions: When combined with tenofovir/emtricitabine in treatment-naive patients, raltegravir produced durable viral suppression and immune restoration that was at least equivalent to efavirenz through 156 weeks of therapy. Both regimens were well tolerated, but raltegravir was associated with fewer drug-related clinical adverse events and smaller elevations in lipid levels. Clinical Trials Registration. NCT00369941.

Objectives: Cytochrome P450 2B6 (CYP2B6) is responsible for the metabolic clearance of efavirenz and single nucleotide polymorphisms (SNPs) in the CYP2B6 gene are associated with efavirenz pharmacokinetics. Since the constitutive androstane receptor (CAR) and the pregnane X receptor (PXR) correlate with CYP2B6 in liver, and a CAR polymorphism (rs2307424) and smoking correlate with efavirenz plasma concentrations, we investigated their association with early (<3 months) discontinuation of efavirenz therapy., Methods: Three hundred and seventy-three patients initiating therapy with an efavirenz-based regimen were included (278 white patients and 95 black patients; 293 male). DNA was extracted from whole blood and genotyping for CYP2B6 (516G → T, rs3745274), CAR (540C → T, rs2307424) and PXR (44477T → C, rs1523130; 63396C → T, rs2472677; and 69789A → G, rs763645) was conducted. Binary logistic regression using the backwards method was employed to assess the influence of SNPs and demographics on early discontinuation., Results: Of the 373 patients, 131 withdrew from therapy within the first 3 months. Black ethnicity [odds ratio (OR) = 0.27; P = 0.0001], CYP2B6 516TT (OR = 2.81; P = 0.006), CAR rs2307424 CC (OR = 1.92; P = 0.007) and smoking status (OR = 0.45; P = 0.002) were associated with discontinuation within 3 months., Conclusions: These data indicate that genetic variability in CYP2B6 and CAR contributes to early treatment discontinuation for efavirenz-based antiretroviral regimens. Further studies are now required to define the clinical utility of these associations.

Background: Long-term effects of abacavir (ABC)-lamivudine (3TC), compared with tenofovir (TDF)-emtricitabine (FTC) with efavirenz (EFV) or atazanavir plus ritonavir (ATV/r), on bone mineral density (BMD) have not been analyzed., Methods: A5224s was a substudy of A5202, in which HIV-infected treatment-naive participants were randomized and blinded to receive ABC-3TC or TDF-FTC with open-label EFV or ATV/r. Primary bone end points included Dual-emission X-ray absorbtiometry (DXA)-measured percent changes in spine and hip BMD at week 96. Primary analyses were intent-to-treat. Statistical tests used the factorial design and included linear regression, 2-sample t, log-rank, and Fisher's exact tests., Results: Two hundred sixty-nine persons randomized to 4 arms of ABC-3TC or TDF-FTC with EFV or ATV/r. At baseline, 85% were male, and 47% were white non-Hispanic; the median HIV-1 RNA load was 4.6 log(10) copies/mL, the median age was 38 years, the median weight was 76 kg, and the median CD4 cell count was 233 cells/μL. At week 96, the mean percentage changes from baseline in spine and hip BMD for ABC-3TC versus TDF-FTC were -1.3% and -3.3% (P = .004) and -2.6% and -4.0% (P = .024), respectively; and for EFV versus ATV/r were -1.7% and -3.1% (P = .035) and -3.1% and -3.4% (P = .61), respectively. Bone fracture was observed in 5.6% of participants. The probability of bone fractures and time to first fracture were not different across components., Conclusions: Compared with ABC-3TC, TDF-FTC-treated participants had significantly greater decreases in spine and hip BMD, whereas ATV/r led to more significant losses in spine, but not hip, BMD than EFV. Clinical Trials Registration. NCT00118898.

Background: Antiretroviral therapy is complicated by drug interactions and contraindications. Novel regimens are needed., Methods: This open label study randomly assigned treatment-naive, human immunodeficiency virus (HIV)-infected subjects to receive tenofovir-emtricitabine with efavirenz (Arm I), with ritonavir-boosted atazanavir (Arm II), or with zidovudine/abacavir (Arm III). Pair-wise comparisons of differences in time-weighted mean change from baseline plasma HIV-RNA to week 48 formed the primary analysis. Treatment arms were noninferior if the upper limit of the 95% confidence interval (CI) was <0.5 log(10) copies/mL. Secondary objectives included virologic, immunologic and safety end points., Results: The intention-to-treat population comprised 322 patients (Arm I, n = 114; Arm II, n = 105; and Arm III, n = 103). Noninferiority for the primary end point was established. Analysis for superiority showed that Arm III was significantly less potent than Arm I (-0.20 log(10) copies/mL; 95% CI, -0.39 to -0.01 log(10) copies/mL; P = .038). The proportions of patients on each of Arm I (95%) and Arm II (96%) with <200 copies/mL were not different (P = .75), but the percentage of patients in Arm III with <200 copies/mL (82%) was significantly lower (P = .005). CD4+ cell counts did not differ. Serious adverse events were more frequent in Arm III (n = 30) than in Arm I or Arm II (n = 15 for each; P = .062)., Conclusions: A novel quadruple nucleo(t)side combination demonstrated significantly less suppression of HIV replication, compared with the suppression demonstrated by standard antiretroviral therapy regimens, although it did meet the predetermined formal definition of noninferiority. Secondary analyses indicated statistically inferior virologic and safety performance. Efavirenz and ritonavir-boosted atazanavir arms were equivalent in viral suppression and safety.

In AIDS Clinical Trials Group A5095, 9% of participants who experienced an adverse event related to efavirenz substituted nevirapine. Most adverse events resolved; 15 participants ultimately discontinued nevirapine therapy. Grade 3/4 hepatotoxicity was observed in 14% of individuals who substituted nevirapine, compared with 6% who continued efavirenz therapy. Substitution of nevirapine because of efavirenz toxicity was generally safe and efficacious. Clinical trials registration. NCT00013520 .

Efavirenz, a non-nucleoside reverse transcriptase inhibitor, has been an important component of the treatment of HIV infection for 10 years and has contributed significantly to the evolution of highly active antiretroviral therapy (HAART). The efficacy of efavirenz has been established in numerous randomized trials and observational studies in HAART-naive patients, including those with advanced infection. In the ACTG A5142 study, efavirenz showed greater virological efficacy than the boosted protease inhibitor (PI), lopinavir. Efavirenz is more effective as a third agent than unboosted PIs or the nucleoside analogue abacavir. Some, but not all, studies have suggested that efavirenz (added to two nucleoside reverse transcriptase inhibitors) is more effective than nevirapine. Virological and immunological responses achieved with efavirenz-based HAART have been maintained for 7 years. Dosing convenience predicts adherence, and studies have demonstrated that patients can be switched from PI-based therapy to simplified, once-daily efavirenz-based regimens without losing virological control. The one-pill, once-daily formulation of efavirenz plus tenofovir and emtricitabine offers a particular advantage in this regard. Efavirenz also retains a role after failure of a first PI-based regimen. Efavirenz is generally well tolerated: rash and neuropsychiatric disturbances are the most notable adverse events. Neuropsychiatric disturbances generally develop early in treatment and they tend to resolve with continued administration, but they are persistent and troubling in a minority of patients. Efavirenz has less effect on plasma lipid profiles than some boosted PIs. Lipodystrophy can occur under treatment with efavirenz but it may be reduced if the concurrent use of thymidine analogues is avoided. Efavirenz resistance mutations (especially K103N) can be selected during long-term treatment, underscoring the importance of good adherence. Recent data have confirmed that efavirenz is a cost-effective option for first-line HAART. In light of these features, efavirenz retains a key role in HIV treatment strategies and is the first-line agent recommended in some guidelines.

Background: Preliminary data suggest that a once-daily combination of lamivudine, didanosine and efavirenz is an effective alternative regimen for antiretroviral-naive HIV-1-infected patients. However, data from randomized trials comparing this combination versus standard first-line regimens are not available yet. In an observational study, we analyse the efficacy and tolerability of didanosine plus lamivudine and efavirenz versus zidovudine plus lamivudine and efavirenz in a cohort of therapy naive patients., Methods: We performed an observational study on prospectively collected data from patients participating in a multicentre Spanish treatment-naive cohort (VACH cohort). Efficacy was assessed comparing time to therapeutic failure and CD4 cell recovery. Safety was analysed comparing the proportion of patients who discontinued therapy for toxicity or any other reason., Results: Overall, 219 patients treated with once-daily didanosine/lamivudine/efavirenz and 409 patients receiving twice-daily zidovudine/lamivudine (Combivir) plus efavirenz were evaluated. By intent-to treat analysis (non-completers and therapeutic change=failure), time to treatment failure was similar in both groups of treatment: 40.0 months (95% CI 23.3-56.8 months) among patients on didanosine/lamivudine/efavirenz and 33.3 months (95% CI 25.6-41.1 months) in patients treated with zidovudine/lamivudine/efavirenz (P=0.253). The risk of failure due to treatment change was almost double among patients treated with zidovudine/lamivudine/efavirenz compared with those who received didanosine/lamivudine/efavirenz., Conclusions: Our data suggest that didanosine/lamivudine/efavirenz is a combination with an efficacy comparable to zidovudine/lamivudine/efavirenz as first-line therapy for HIV infection. The risk of treatment change was significantly higher among patients treated with zidovudine/lamivudine/efavirenz than in those starting therapy with didanosine/lamivudine/efavirenz.

Background: The combination of didanosine, lamivudine, and efavirenz (ddI/3TC/EFV) for the initial treatment of human immunodeficiency virus type 1 (HIV-1) infection has been insufficiently analyzed in clinical trials., Methods: We conducted an open-label, randomized study to compare the noninferiority of ddI/3TC/EFV with the lamivudine-zidovudine tablet and EFV (COM/EFV), both administered with food to improve tolerability and convenience. Patients were stratified by HIV-1 RNA level of <5.0 log(10) or > or =5.0 log(10) copies/mL. The primary end point was the percentage of patients with an HIV-1 RNA level of <50 copies/mL at week 48, determined by intention-to-treat analysis., Results: Three hundred sixty-nine patients were randomized: 186 for ddI/3TC/EFV treatment and 183 for COM/EFV treatment. Both groups were well matched in terms of baseline characteristics; 19.3% of patients received a Centers for Disease Control and Prevention assessment of clinical category C, median HIV RNA level was 5.0 log(10) copies/mL, and median CD4(+) cell count was 208 cells/microL. At week 48, by intention-to-treat analysis, 70% of patients in the ddI/3TC/EFV group and 63% of patients in the COM/EFV group had an HIV-1 RNA level of <50 copies/mL (treatment difference, 7.1%; 95% confidence interval, -2.39% to 16.59%). Fourteen patients (8%) in the ddI/3TC/EFV arm (not the COM/EFV arm) and 26 patients (14%) in the COM/EFV arm (not the ddI/3TC/EFV arm) [corrected] discontinued the study medication because of adverse events (P = .046). One patient (1%) in the ddI/3TC/EFV arm and 11 patients (6%) in the COM/EFV arm discontinued medication because of hematological toxicity (P = .003)., Conclusions: At week 48, ddI/3TC/EFV administered once per day with food did not have results inferior to those of COM/EFV treatment. A statistically significantly higher proportion of patients in the COM/EFV arm than in the ddI/3TC/EFV arm discontinued therapy because of adverse events, mainly because of hematological toxicity., Clinical Trials Registration: NCT00256828.

Background: Vicriviroc (VCV) is a CCR5 antagonist with nanomolar activity against human immunodeficiency virus (HIV) replication in vitro and in vivo. We report the results of a phase II dose-finding study of VCV plus dual nucleoside reverse-transcriptase inhibitors (NRTIs) in the treatment-naive HIV-1-infected subjects., Methods: This study was a randomized, double-blind, placebo-controlled trial that began with a 14-day comparison of 3 dosages of VCV with placebo in treatment-naive subjects infected with CCR5-using HIV-1. After 14 days of monotherapy, lamivudine/zidovudine was added to the VCV arms; subjects receiving placebo were treated with efavirenz and lamivudine/zidovudine; the planned treatment duration was 48 weeks., Results: Ninety-two subjects enrolled. After 14 days of once-daily monotherapy, the mean viral loads decreased from baseline values by 0.07 log(10) copies/mL in the placebo arm, 0.93 log(10) copies/mL in the VCV 25 mg arm, 1.18 log(10) copies/mL in the VCV 50 mg arm, and 1.34 log(10) copies/mL in the VCV 75 mg arm (P < .001 for each VCV arm vs. the placebo arm). The combination-therapy portion of the study was stopped because of increased rates of virologic failure in the VCV 25 mg/day arm (relative hazard [RH], 21.6; 95% confidence interval [CI], 2.8-168.9) and the VCV 50 mg/day arm (RH, 11.7; 95% CI, 1.5-92.9), compared with that in the control arm., Conclusions: VCV administered with dual NRTIs in treatment-naive subjects with HIV-1 infection had increased rates of virologic failure, compared with efavirenz plus dual NRTIs. No treatment-limiting toxicity was observed. Study of higher doses of VCV as part of combination therapy is warranted.

Highly active antiretroviral therapy plays a central role in the development of lipodystrophy syndrome, which may affect up to 50% of patients depending on the diagnostic criteria used. Most protease inhibitors and nucleoside reverse transcriptase inhibitors (NRTIs) are involved in body fat changes and associated metabolic disturbances. In contrast, non-NRTIs have not been directly related to the onset of this syndrome. One of the most widely used methods to evaluate body fat changes is dual-energy X-ray absorptiometry (DEXA), which can detect differences in the distribution of body fat in patients with and without lipodystrophy. New information from a randomized open-label clinical trial suggests that efavirenz could have greater potential for causing lipoatrophy than lopinavir+ritonavir. This paper examines the impact of efavirenz on adipose tissue and body fat composition in order to evaluate whether this drug plays a role in the development of lipodystrophy. We have focused on the evidence obtained from comparative randomized clinical trials that use an objective measurement of fat distribution, such as DEXA. We analysed available in vitro data and evidence from non-comparative clinical trials.

Background: Efavirenz and lopinavir/ritonavir are both recommended antiretroviral agents for combination first-line therapy, although information on direct comparisons between them is scarce. A retrospective longitudinal study from the VACH cohort comparing both regimens was performed., Methods: Efficacy was examined comparing time to virological failure, CD4 recovery and clinical progression. Tolerability was examined comparing time to treatment discontinuation for any reason and for toxicity. Survival analysis was conducted using the Kaplan-Meier method, and standard and weighted Cox regression models., Results: A total of 1550 antiretroviral-naive patients starting a two-nucleoside reverse transcriptase inhibitor regimen plus either efavirenz (n = 1159) or lopinavir/ritonavir (n = 391) were included in the study. At baseline, patients starting lopinavir/ritonavir had higher HIV-1 RNA and lower CD4+ cell counts. There was no difference in the adjusted hazards of virological failure [efavirenz versus lopinavir/ritonavir hazard ratio (HR) = 0.93, 95% confidence interval (CI): 0.77-1.12, P = 0.43], CD4 recovery (HR = 1.11, 95% CI: 0.95-1.30, P = 0.19) and clinical progression (HR = 0.71, 95% CI: 0.39-1.31, P = 0.27). There was an increased risk of discontinuation for any reason or for toxicity for lopinavir/ritonavir (HR = 2.10, 95% CI: 1.40-3.15, P = 0.0003). CD4 recovery with both drugs was also similar in the lowest CD4 strata. A higher risk of early hypertriglyceridaemia was associated with lopinavir/ritonavir-based regimens., Conclusions: Our study suggests similar virological efficacy for efavirenz- or lopinavir/ritonavir-based first-line antiretroviral regimens, but an increased risk of discontinuation because of toxicity in case of lopinavir/ritonavir-based therapy. Immunological outcome appeared similar with both regimens.

Objectives: To obtain data on the pharmacokinetics of efavirenz in children in clinical practice., Methods: HIV-1-infected children received efavirenz capsules or tablets in accordance with manufacturer's dosing recommendations. Plasma was collected at regular visits and analysed by HPLC. The therapeutic range of efavirenz was defined as 1.0-4.0 mg/L., Results: Thirty-three children were included. Median (range) age, body weight, dose and dose/kg were 8.2 (2.1-16.7) years, 24 (12-62) kg, 300 (200-800) mg and 13.3 (9.7-22.5) mg/kg, respectively. Median (range) efavirenz plasma concentration at first sampling was 2.8 (0.13-11.6) mg/L. Plasma concentrations were not dependent on age (P = 0.97) or dose/kg (P = 0.87). A total of 307 efavirenz plasma concentrations were determined. Forty-five samples (14.7%) contained >4.0 mg/L, and 27 samples (8.8%) contained <1.0 mg/L. Eight children (24%) reported persistent adverse events probably caused by efavirenz [concentration problems (5), sleep disorder (1), psychotic reaction (1) and seizure (1)]; six discontinued efavirenz for this reason. A non-significant trend existed towards a higher proportion of toxic efavirenz plasma concentrations (>4.0 mg/L) in subjects who reported efavirenz adverse events: 25.9% versus 12.8% (P = 0.23; t-test). Viral load was <50 copies/mL in all 27 subjects who continued efavirenz, despite occasional subtherapeutic efavirenz plasma concentrations in 12 children. The occasional subtherapeutic levels suggest that temporal non-adherence was present., Conclusions: Efavirenz as part of highly active antiretroviral therapy was highly effective in children able to tolerate the drug. Therapeutic drug monitoring (TDM) as part of toxicity management may prevent discontinuation in a subset of patients. Temporal non-adherence occurs frequently. TDM may allow initiation of adherence interventions before viral load becomes detectable.

Clearance and adverse effects of efavirenz are associated with CYP2B6-G516T polymorphism. Little is known about the prevalence of genotypes and implications for screening in children. We report (to our knowledge, for the first time in a child) the emergence of psychosis in a 12-year old white girl with an increased efavirenz concentration and heterozygous gene polymorphism of the CYP2B6-G516T.

Although there is a presumed drug-drug interaction between itraconazole and nonnucleoside reverse-transcriptase inhibitors, the medical literature lacks such documentation. We describe a drug-drug interaction between itraconazole and efavirenz in a patient with disseminated histoplasmosis and acquired immunodeficiency syndrome (AIDS). The drug combination resulted in persistently elevated urinary Histoplasma antigen levels and subtherapeutic plasma itraconazole concentrations. Changing treatment from efavirenz to a protease inhibitor was accompanied by improvements in the desired urinary Histoplasma antigen level and plasma itraconazole concentration.