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Item does not contain fulltext Nirmatrelvir–ritonavir (NMV/r) is now being used to treat high-risk patients with mild to moderate COVID-19. This article provides advice to clinicians regarding recognition of medications likely to interact with NMV/r and suggests approaches to managing such drug–drug interactions. An algorithm is provided to assist in decision making.

Global use of dexamethasone in COVID-19 patients has revealed a poor understanding of the drug–drug interaction (DDI) potential of dexamethasone, particularly with antiretroviral agents (ARVs). Dexamethasone is both a substrate and a dose-dependent inducer of cytochrome P450 3A4 (CYP3A4). As many ARVs are substrates and/or inhibitors or inducers of CYP3A4, there is concern about DDIs with dexamethasone either as a perpetrator or a victim. Assessment of DDIs that involve dexamethasone is complex as dexamethasone is used at a range of daily doses (generally 0.5 up to 40 mg) and a treatment course can be short, long, or intermittent. Moreover, DDIs with dexamethasone have been evaluated only for a limited number of drugs. Here, we summarize the available in vitro and in vivo data on the interaction potential of dexamethasone and provide recommendations for the management of DDIs with ARVs, considering various dexamethasone dosages and treatment durations.

Nearly all HIV PIs and the integrase inhibitor elvitegravir require a pharmacokinetic enhancer in order to achieve therapeutic plasma concentrations at the desired dose and frequency. Whereas ritonavir has been the only available pharmacokinetic enhancer for more than a decade, cobicistat has recently emerged as an alternative boosting agent. Cobicistat and ritonavir are equally strong inhibitors of cytochrome P450 (CYP) 3A4 and consequently were shown to be equivalent pharmacokinetic enhancers for elvitegravir and for the PIs atazanavir and darunavir. Since cobicistat is a more selective CYP inhibitor than ritonavir and is devoid of enzyme-inducing properties, differences are expected in their interaction profiles with some co-medications. Drugs whose exposure might be altered by ritonavir but unaltered by cobicistat are drugs primarily metabolized by CYP1A2, CYP2B6, CYP2C8, CYP2C9 and CYP2C19 or drugs undergoing mainly glucuronidation. Thus, co-medications should be systematically reviewed when switching the pharmacokinetic enhancer to anticipate potential dosage adjustments.

Although direct‐acting antivirals (DAAs) for chronic hepatitis C virus (HCV) infection are highly efficacious and safe, treatment initiation is often limited in patients with neuropsychiatric disorders due to concerns over reduced treatment adherence and drug–drug interactions. Here, we report adherence, efficacy, safety and patient‐reported outcomes (PROs) from an integrated analysis of registrational studies using the pangenotypic DAA regimen of glecaprevir and pibrentasvir (G/P). Patients with chronic HCV genotypes 1‐6 infection with compensated liver disease (with or without cirrhosis) receiving G/P for 8, 12 or 16 weeks were included in this analysis. Patients were classified as having a psychiatric disorder based on medical history and/or co‐medications. Primary analyses assessed treatment adherence, efficacy (sustained virologic response at post‐treatment week 12; SVR12), safety and PROs. Among 2522 patients receiving G/P, 789 (31%) had a psychiatric disorder with the most common diagnoses being depression (64%; 506/789) and anxiety disorders (27%; 216/789). Treatment adherence was comparably high (>95%) in patients with and without psychiatric disorders. SVR12 rates were 97.3% (768/789; 95% CI = 96.2‐98.5) and 97.5% (1689/1733; 95% CI = 96.7‐98.2) in patients with and without psychiatric disorders, respectively. Among patients with psychiatric disorders, SVR12 rates remained >96% by individual psychiatric diagnoses and co‐medication classes. Overall, most adverse events (AEs) were mild‐to‐moderate in severity with serious AEs and AEs leading to G/P discontinuation occurring at similarly low rates in both patient populations. In conclusion, G/P treatment was highly efficacious, well‐tolerated and demonstrated high adherence rates in patients with chronic HCV infection and psychiatric disorders.

Combined antiretroviral treatments have significantly improved the morbidity and mortality related to HIV infection, thus transforming HIV infection into a chronic disease; however, the efficacy of antiretroviral treatments is highly dependent on the ability of infected individuals to adhere to life-long drug combination therapies. A major milestone in HIV treatment is the marketing of the long-acting intramuscular antiretroviral drugs cabotegravir and rilpivirine, allowing for infrequent drug administration, with the potential to improve adherence to therapy and treatment satisfaction. Intramuscular administration of cabotegravir and rilpivirine leads to differences in pharmacokinetics and drug–drug interaction (DDI) profiles compared with oral administration. A notable difference is the long elimination half-life with intramuscular administration, which reaches 5.6–11.5 weeks for cabotegravir and 13–28 weeks for rilpivirine, compared with 41 and 45 h, respectively, with their oral administration. Cabotegravir and rilpivirine have a low potential to cause DDIs, however these drugs can be victims of DDIs. Cabotegravir is mainly metabolized by UGT1A1, and rilpivirine is mainly metabolized by CYP3A4, therefore these agents are susceptible to DDIs with inhibitors, and particularly inducers of drug-metabolizing enzymes. Intramuscular administration of cabotegravir and rilpivirine has the advantage of eliminating DDIs occurring at the gastrointestinal level, however interactions can still occur at the hepatic level. This review provides insight on the intramuscular administration of drugs and summarizes the pharmacology of long-acting cabotegravir and rilpivirine. Particular emphasis is placed on DDI profiles after oral and intramuscular administration of these antiretroviral drugs.

Contains fulltext : 232502.pdf (Publisher’s version ) (Open Access) INTRODUCTION: In December 2019, an outbreak of a novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) began, resulting in a number of antivirals and immune modulators being repurposed to treat the associated coronavirus disease 2019 (COVID-19). Many patients requiring treatment for COVID-19 may have either pre-existing renal or hepatic disease or experience acute renal/hepatic injury as a result of the acute infection. Altered renal or hepatic function can significantly affect drug concentrations of medications due to impaired drug metabolism and excretion, resulting in toxicity or reduced efficacy. The aim of this paper is to review the pharmacokinetics and available study data for the experimental COVID-19 therapies in patients with any degree of renal or hepatic impairment to make recommendations for dosing. METHODS: COVID-19 agents included in these recommendations were listed as primaries on the University of Liverpool COVID-19 drug interaction website ( www.covid19-druginteractions.org ), initially identified from Clinicialtrials.gov and ChicCTR.org.cn. A literature search was performed using PubMed and EMBASE as well as product licences and pharmacokinetic databases. FINDINGS: Remdesivir, dexamethasone, azithromycin, favipiravir, lopinavir/ritonavir, atazanavir, hydroxychloroquine, interferon beta, ribavirin, tocilizumab, anakinra and sarilumab were identified as experimental drugs being used in COVID-19 trials as of November 2020. Limited study data was found for these drugs in patients with renal or hepatic impairment for COVID-19 or other indications. Recommendations were made based on available data, consideration of pharmacokinetic properties (including variability), the dosing and anticipated treatment duration of each regimen in COVID-19 and known toxicities. CONCLUSION: Dosing of drugs used to treat COVID-19 in patients with renal or hepatic impairment is complex. These recommendations were produced to provide guidance to clinicians worldwide who are treating patients with COVID-19, many of whom will have some degree of acute or chronic renal or hepatic impairment.

In a recent issue of Br J Clin Pharmacol Smith et al1 published an outstanding commentary titled ‘Dosing will be a key success factor in repurposing antivirals for Covid-19’. They highlighted that the success in our repurposing efforts will be dependent on ‘getting the dose right’ for drugs which have been developed for different indications and stressed some of the unique challenges of treating this particular disease. They pointed the reader to lopinavir/ritonavir (LPV/r) as an example of a repurposed antiviral and the limited experience of this drug regimen (and other treatments) in the elderly population with comorbidities – ie those most at risk from Covid-19. It is on the issue of comorbidities, polypharmacy and drug-drug interactions (DDIs) that we wish to comment.

The urgent global public health need presented by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) has brought scientists from diverse backgrounds together in an unprecedented international effort to rapidly identify interventions. There is a pressing need to apply clinical pharmacology principles and this has already been recognized by several other groups. However, one area that warrants additional specific consideration relates to plasma and tissue protein binding that broadly influences pharmacokinetics and pharmacodynamics. The principles of free drug theory have been forged and applied across drug development but are not currently being routinely applied for SARS-CoV-2 antiviral drugs. Consideration of protein binding is of critical importance to candidate selection but requires correct interpretation, in a drug-specific manner, to avoid either underinterpretation or overinterpretation of its consequences. This paper represents a consensus from international researchers seeking to apply historical knowledge, which has underpinned highly successful antiviral drug development for other viruses, such as HIV and hepatitis C virus for decades.

Intense efforts are underway to evaluate potential therapeutic agents for the treatment of COVID-19. In order to respond quickly to the crisis, the repurposing of existing drugs is the primary pharmacological strategy. Despite the urgent clinical need for these therapies, it is imperative to consider potential safety issues. This is important due to the harm-benefit ratios that may be encountered when treating COVID-19, which can depend on the stage of the disease, when therapy is administered and underlying clinical factors in individual patients. Treatments are currently being trialled for a range of scenarios from prophylaxis (where benefit must greatly exceed risk) to severe life-threatening disease (where a degree of potential risk may be tolerated if it is exceeded by the potential benefit). In this perspective, we have reviewed some of the most widely researched repurposed agents in order to identify potential safety considerations using existing information in the context of COVID-19.

BACKGROUND Owing to an increase in digital technologies in health care, recently leveraged by the COVID-19 pandemic, physicians are required to use these technologies appropriately and to be familiar with their implications on patient care, the health system, and society. Therefore, medical students should be confronted with digital health during their medical education. However, corresponding teaching formats and concepts are still largely lacking in the medical curricula. OBJECTIVE This study aims to introduce digital health as a curricular module at a German medical school and to identify undergraduate medical competencies in digital health and their suitable teaching methods. METHODS We developed a 3-week curricular module on digital health for third-year medical students at a large German medical school, taking place for the first time in January 2020. Semistructured interviews with 5 digital health experts were recorded, transcribed, and analyzed using an abductive approach. We obtained feedback from the participating students and lecturers of the module through a 17-item survey questionnaire. RESULTS The module received overall positive feedback from both students and lecturers who expressed the need for further digital health education and stated that the field is very important for clinical care and is underrepresented in the current medical curriculum. We extracted a detailed overview of digital health competencies, skills, and knowledge to teach the students from the expert interviews. They also contained suggestions for teaching methods and statements supporting the urgency of the implementation of digital health education in the mandatory curriculum. CONCLUSIONS An elective class seems to be a suitable format for the timely introduction of digital health education. However, a longitudinal implementation in the mandatory curriculum should be the goal. Beyond training future physicians in digital skills and teaching them digital health’s ethical, legal, and social implications, the experience-based development of a critical digital health mindset with openness to innovation and the ability to assess ever-changing health technologies through a broad transdisciplinary approach to translate research into clinical routine seem more important. Therefore, the teaching of digital health should be as practice-based as possible and involve the educational cooperation of different institutions and academic disciplines.

The development of therapeutic agents against SARS-CoV-2/COVID-19 faces numerous barriers and a multidisciplinary approach to evaluating drug efficacy and toxicity is essential. Experimental and preclinical data should be integrated into a comprehensive analysis, where drug potency, the timing of therapy initiation, drug combinations, variability in systemic and local drug exposure and short- and long-term toxicities represent fundamental factors for the rational identification of candidates and prioritization of clinical investigations. Although the identification of SARS-CoV-2 therapeutics is a priority, rigorous and transparent methodologies are crucial to ensure that accelerated research programmes result in high-quality and reproducible findings.

In a recent issue of Br J Clin Pharmacol Smith et al1 published an outstanding commentary titled ‘Dosing will be a key success factor in repurposing antivirals for Covid-19’. They highlighted that the success in our repurposing efforts will be dependent on ‘getting the dose right’ for drugs which have been developed for different indications and stressed some of the unique challenges of treating this particular disease. They pointed the reader to lopinavir/ritonavir (LPV/r) as an example of a repurposed antiviral and the limited experience of this drug regimen (and other treatments) in the elderly population with comorbidities – ie those most at risk from Covid-19. It is on the issue of comorbidities, polypharmacy and drug-drug interactions (DDIs) that we wish to comment.

There is a rapidly expanding literature on thein vitroantiviral activity of drugs that may be repurposed for therapy or chemoprophylaxis against SARS-CoV-2. However, this has not been accompanied by a comprehensive evaluation of the ability of these drugs to achieve target plasma and lung concentrations following approved dosing in humans. Moreover, most publications have focussed on 50% maximum effective concentrations (EC50), which may be an insufficiently robust indicator of antiviral activity because of marked differences in the slope of the concentration-response curve between drugs. Accordingly,in vitroanti-SARS-CoV-2 activity data was digitised from all available publications up to 13thApril 2020 and used to recalculate an EC90value for each drug. EC90values were then expressed as a ratio to the achievable maximum plasma concentrations (Cmax) reported for each drug after administration of the approved dose to humans (Cmax/EC90ratio). Only 14 of the 56 analysed drugs achieved a Cmax/EC90ratio above 1 meaning that plasma Cmax concentrations exceeded those necessary to inhibit 90% of SARS-CoV-2 replication. A more in-depth assessment of the putative agents tested demonstrated that only nitazoxanide, nelfinavir, tipranavir (boosted with ritonavir) and sulfadoxine achieved plasma concentrations above their reported anti-SARS-CoV-2 activity across their entire approved dosing interval at their approved human dose. For all drugs reported, the unbound lung to plasma tissue partition coefficient (KpUlung) was also simulated and used along with reported Cmax and fraction unbound in plasma to derive a lung Cmax/EC50as a better indicator of potential human efficacy (lung Cmax/EC90ratio was also calculable for a limited number of drugs). Using this parameter hydroxychloroquine, chloroquine, mefloquine, atazanavir (boosted with ritonavir), tipranavir (boosted with ritonavir), ivermectin, azithromycin and lopinavir (boosted with ritonavir) were all predicted to achieve lung concentrations over 10-fold higher than their reported EC50. This analysis was not possible for nelfinavir because insufficient data were available to calculate KpUlungbut nitozoxanide and sulfadoxine were also predicted to exceed their reported EC50by 3.1- and 1.5-fold in lung, respectively. The antiviral activity data reported to date have been acquired under different laboratory conditions across multiple groups, applying variable levels of stringency. However, this analysis may be used to select potential candidates for further clinical testing, while deprioritising compounds which are unlikely to attain target concentrations for antiviral activity. Future studies should focus on EC90values and discuss findings in the context of achievable exposures in humans, especially within target compartments such as the lung, in order to maximise the potential for success of proposed human clinical trials.

Introduction The availability of potent antiretroviral therapy has transformed HIV infection into a chronic disease such that people living with HIV (PLWH) have a near normal life expectancy. However, there are continuing challenges in managing HIV infection, particularly in older patients, who often experience age‐related comorbidities resulting in complex polypharmacy and an increased risk for drug‐drug interactions. Furthermore, age‐related physiological changes may affect the pharmacokinetics and pharmacodynamics of both antiretrovirals and comedications thereby predisposing elderly to adverse drug reactions. This review provides an overview of the therapeutic challenges when treating elderly PLWH (i.e. >65 years). Particular emphasis is placed on drug‐drug interactions and other common prescribing issues (i.e. inappropriate drug use, prescribing cascade, drug‐disease interaction) encountered in elderly PLWH. Discussion Prescribing issues are common in elderly PLWH due to the presence of age‐related comorbidities, organ dysfunction and physiological changes leading to a higher risk for drug‐drug interactions, drugs dosage errors and inappropriate drug use. Conclusions The high prevalence of prescribing issues in elderly PLWH highlights the need for ongoing education on prescribing principles and the optimal management of individual patients. The knowledge of adverse health outcomes associated with polypharmacy and inappropriate prescribing should ensure that there are interventions to prevent harm including medication reconciliation, medication review and medication prioritization according to the risks/benefits for each patient.

Background With the introduction of direct-acting antivirals (DAAs) for hepatitis C virus (HCV) infection, drug–drug interactions (DDIs) emerged as significant challenge. Since then, HCV therapy and the infected population have rapidly changed. So far, very limited data are available regarding the clinical relevance of DDIs when using most modern DAA regimens. We aimed to assess how the importance of DDIs has evolved over time. Methods From January 2014 to July 2018, 668 consecutive HCV patients were evaluated for their outpatient medication and assessed for DDIs with DAAs. Different time periods were defined based on market approval of key DAAs: A (01/2014–11/2014), B (11/2014–08/2016), and C (08/2016–07/2018). Results The frequency of patients with real-world DDIs was highest in period B (A: 37.1%, B: 49.6%, C: 38.8%). The recently approved DAAs (period C) theoretically showed a lower DDI risk profile. However, real-world DDIs were still comparable to period A, as HCV patients’ characteristics changed (eg, age ≥75 years: A: 3.1%, B: 9.8%, C: 5.6%; polypharmacy/patients with ≥8 drugs: A: 11.1%, B: 15.2%, C: 17.2%). Furthermore, although DDIs via CYP 3A4 became less important for some modern regimens, other mechanisms like an altered pH value in the stomach, causing reduced bioavailability, evolved. Relevant DDIs most frequently occurred with proton pump inhibitors, metamizole, statins, and carvedilol. Conclusions DDIs during antiviral treatment still affect about 40% of HCV patients. The lower DDI potential of modern DAA regimens is partly counteracted by changing patient characteristics. Therefore, DDIs should not be underestimated.

Contains fulltext : 229144.pdf (Publisher’s version ) (Closed access) As global health services respond to the coronavirus pandemic, many prescribers are turning to experimental drugs. This review aims to assess the risk of drug-drug interactions in the severely ill COVID-19 patient. Experimental therapies were identified by searching ClinicalTrials.gov for 'COVID-19', '2019-nCoV', '2019 novel coronavirus' and 'SARS-CoV-2'. The last search was performed on 30 June 2020. Herbal medicines, blood-derived products and in vitro studies were excluded. We identified comorbidities by searching PubMed for the MeSH terms 'COVID-19', 'Comorbidity' and 'Epidemiological Factors'. Potential drug-drug interactions were evaluated according to known pharmacokinetics, overlapping toxicities and QT risk. Drug-drug interactions were graded GREEN and YELLOW: no clinically significant interaction; AMBER: caution; RED: serious risk. A total of 2378 records were retrieved from ClinicalTrials.gov, which yielded 249 drugs that met inclusion criteria. Thirteen primary compounds were screened against 512 comedications. A full database of these interactions is available at www.covid19-druginteractions.org. Experimental therapies for COVID-19 present a risk of drug-drug interactions, with lopinavir/ritonavir (10% RED, 41% AMBER; mainly a perpetrator of pharmacokinetic interactions but also risk of QT prolongation particularly when given with concomitant drugs that can prolong QT), chloroquine and hydroxychloroquine (both 7% RED and 27% AMBER, victims of some interactions due to metabolic profile but also perpetrators of QT prolongation) posing the greatest risk. With management, these risks can be mitigated. We have published a drug-drug interaction resource to facilitate medication review for the critically ill patient.

Aims Direct-acting antiviral agents (DAAs) for the treatment of hepatitis C (HCV) can be associated with drug-drug interactions (DDIs) with concomitant medications. The practical clinical implications of such DDIs are poorly understood. We assessed the clinical impact of possible pharmacokinetic (PK) interactions between simeprevir and frequently prescribed concomitant medications. Methods This post hoc analysis pooled data from nine studies which evaluated simeprevir (SMV)-based interferon-free HCV treatment. Three classes of frequently used concomitant medications of interest (CMOIs) were analysed [antihypertensive drugs (AHDs), anxiolytic drugs (AXDs) and lipid-lowering drugs (LLDs)] and categorized as amber or green according to their DDI potential with SMV (green: no DDIs; amber: potential/known PK interactions). Concomitant medications not recommended to be coadministered with SMV were not included. The composite primary endpoint was defined as the frequency of either discontinuation, interruption or dose modification of the CMOI during 12 weeks of SMV treatment. Results Few patients met the composite endpoint in the various subgroups. Patients on amber CMOIs tended to experience CMOI modification more often (13.4-19.4%) than those on green CMOIs (3.1-10.8%). There was no difference in the frequency of adverse events between patients taking green and those taking amber CMOIs. Conclusions In this large pooled analysis, coadministration of the evaluated commonly prescribed medications with known or potential PK interactions with SMV was manageable and resulted in few adjustments of concomitant medications. Our method could serve as a blueprint for the evaluation of the impact of DDIs.

Reduced levonorgestrel concentrations from the levonorgestrel contraceptive implant was previously seen when given concomitantly with efavirenz. We sought to assess whether single nucleotide polymorphisms (SNPs) in genes involved in efavirenz and nevirapine metabolism were linked to these changes in levonorgestrel concentration. SNPs in CYP2B6, CYP2A6, NR1I2, and NR1I3 were analyzed. Associations of participant demographics and genotype with levonorgestrel pharmacokinetics were evaluated in HIV-positive women using the levonorgestrel implant plus efavirenz- or nevirapine-based antiretroviral therapy (ART), in comparison to ART-naive women using multivariate linear regression. Efavirenz group: CYP2B6 516G>T was associated with lower levonorgestrel log10 Cmax and log10 AUC. CYP2B6 15582C>T was associated with lower log10 AUC. Nevirapine group: CYP2B6 516G>T was associated with higher log10 Cmax and lower log10 Cmin . Pharmacogenetic variations influenced subdermal levonorgestrel pharmacokinetics in HIV-positive women, indicating that the magnitude of the interaction with non-nucleoside reverse transcriptase inhibitors (NNRTIs) is influenced by host genetics.

Long-acting injectable antiretrovirals represent a pharmacological alternative to oral formulations and an innovative clinical option to address adherence and reduce drug costs. Clinical studies in children and adolescents are characterised by ethical and logistic barriers complicating the identification of dose optimisation. Physiologically-based pharmacokinetic modelling represents a valuable tool to inform dose finding prior to clinical trials. The objective of this study was to simulate potential dosing strategies for existing long-acting injectable depot formulations of cabotegravir and rilpivirine in children and adolescents (aged 3–18 years) using physiologically-based pharmacokinetic modelling. Whole-body physiologically-based pharmacokinetic models were developed to represent the anatomical, physiological and molecular processes and age-related changes in children and adolescents through allometric equations. Models were validated for long-acting injectable intramuscular cabotegravir and rilpivirine in adults. Subsequently, the anatomy and physiology of children and adolescents were validated against available literature. The optimal doses of monthly administration of cabotegravir and rilpivirine were identified in children and adolescents, to achieve trough concentrations over the target concentrations derived in a recent efficacy trial of the same formulations. Pharmacokinetic data generated through the physiologically-based pharmacokinetic simulations were similar to observed clinical data in adults. Optimal doses of long-acting injectable antiretrovirals cabotegravir and rilpivirine were predicted using the release rate observed for existing clinical formulations, for different weight groups of children and adolescents. The intramuscular loading dose and maintenance dose of cabotegravir ranged from 200 to 600 mg and from 100 to 250 mg, respectively, and for rilpivirine it ranged from 250 to 550 mg and from 150 to 500 mg, respectively, across various weight groups of children ranging from 15 to 70 kg. The reported findings represent a rational platform for the identification of suitable dosing strategies and can inform prospective clinical investigation of long-acting injectable formulations in children and adolescents.

Long-acting injectable antiretroviral agents are being developed for HIV-1 prevention. The MWRI-01 study was done to characterise the safety, acceptability, and pharmacokinetic and pharmacodynamic profile of long-acting rilpivirine.We did a phase 1 open-label study at the University of Pittsburgh. We enrolled healthy individuals (aged 18-45 years) who were seronegative for HIV-1. Participants were assigned alternately one intramuscular dose of either 1200 mg or 600 mg long-acting rilpivirine, beginning with the 1200 mg dose. We obtained plasma specimens, genital and rectal fluids, and tissue samples (rectal, cervical, and vaginal) before and after exposure to long-acting rilpivirine for assessment of pharmacokinetics and ex-vivo biopsy challenge with HIV-1. Our primary objective was to characterise product safety, and the analysis included all enrolled participants. This trial is registered with ClinicalTrials.gov, number NCT01656018.36 participants were enrolled into the study, of whom 24 were women and 12 men. 12 women and six men received each dose. 204 adverse events were reported among the 36 participants, of which 200 (98%) were grade 1-2. The most common adverse event was injection site reaction. All grade 3 and 4 adverse events were deemed not related to rilpivirine. Geometric mean (90% CI) concentrations in plasma of rilpivirine at day 28 post dose were 53 ng/mL (38-67) in women and 43 ng/mL (23-63) in men for the 1200 mg dose and 28 ng/mL (19-37) in women and 17 ng/mL (9-24) in men for the 600 mg dose. The tissue-to-plasma ratio for rilpivirine in rectal tissue was about two-fold higher than in vaginal and cervical tissue (1·10-1·53 vs 0·61-0·72 and 0·50-0·71, respectively). Exposure to long-acting rilpivirine suppressed viral replication significantly in rectal tissue (p0·0001), and this suppression persisted for up to 4 months. By contrast, no viral suppression was seen in cervical or vaginal tissue.Ongoing research will characterise longer term safety and acceptability of multiple injections and help ascertain whether long-acting rilpivirine should advance to assessment of efficacy in preventing HIV-1 infection.BillMelinda Gates Foundation.

The MWRI-01 study characterized the safety, acceptability, pharmacokinetic (PK), and pharmacodynamic (PD) profile of rilpivirine (RPV) long acting (LA) in a model of preexposure prophylaxis (PrEP). Prospective, open-label Phase 1 study. The safety and acceptability of three repeated doses of RPV LA were monitored. Blood, tissue (rectal, cervical, and vaginal), and biological fluids (vaginal and endocervical) were collected at baseline and at 1- to 2-month intervals throughout the study for PK and PD assessment. Eight women and four men received three intramuscular doses of 1,200 mg of RPV LA given 8 weeks apart. There were a total of 195 adverse events (AEs) reported, of which 138 (70.8%) were Grade 1 and 55 (28.2%) were Grade 2. The most common AE was injection site pain. Geometric mean (90% confidence interval) plasma RPV concentrations at 56 days after the first and third doses were 39 (33-45) ng/mL (female)/29 (17-40) ng/mL (male) and 59 (45-62) ng/mL (female)/40 (30-51) ng/mL (male), respectively. Exposure to RPV LA was associated with significant inhibition of HIV-1

The aim of this study was to determine the utility of dried blood spots (DBS) compared with conventional plasma collection methods for characterization of efavirenz pharmacokinetics, in the setting of a large-scale, global clinical trial (ENCORE1).Six hundred thirty patients were recruited from 38 sites and had single matched whole blood DBS and plasma samples (mid-dose interval) taken at weeks 4 and 12 of treatment. In addition, a subgroup of patients underwent intensive DBS and plasma sampling (0-24 hours) to provide full-profile data for pharmacokinetic parameters. Efavirenz concentrations were determined by validated high-performance liquid chromatography-mass spectrometry methods. A DBS-predicted plasma concentration was derived and linear regression and Bland-Altman plots were used to compare DBS-predicted plasma concentrations with that of measured plasma concentrations.Efavirenz DBS and plasma concentrations were significantly correlated (R = 0.904, P < 0.001; n = 1094), and DBS concentrations were, on average, 53% ± 9.5% lower than plasma. In the main study, the DBS-predicted plasma values significantly underestimated the true measured concentration of efavirenz in plasma; the mean difference (95% confidence interval) between efavirenz DBS-predicted concentrations and measured plasma concentrations was -0.451 mg/L (-0.504 to -0.398) at week 4 (n = 561). However, in the intensive study, the mean difference was only 0.086 mg/L (-0.006 to 0.178) at 12 hours after dose (n = 46) and was not statistically significant.Our data show a high correlation between measurements of efavirenz concentrations in plasma and in DBS. However, DBS concentrations significantly underestimated the true measured plasma concentrations in the sparse samples taken in this large multinational ENCORE1 trial.

Contains fulltext : 202606.pdf (Publisher’s version ) (Closed access)

It has been estimated by the World Health Organization (WHO) that over 71 million people were infected with the hepatitis C virus (HCV) in 2015. Since then, a number of highly effective direct-acting antiviral (DAA) regimens have been licensed for the treatment of chronic HCV infection: sofosbuvir/daclatasvir, sofosbuvir/ledipasvir, elbasvir/grazoprevir, sofosbuvir/velpatasvir, glecaprevir/pibrentasvir, and sofosbuvir/velpatasvir/voxilaprevir. With these treatment regimens, almost all chronic HCV-infected patients, even including prior DAA failures, can be treated effectively and safely. It is therefore likely that further development of DAAs will be limited. In this descriptive review we provide an overview of the clinical pharmacokinetic characteristics of currently available DAAs by describing their absorption, distribution, metabolism, and excretion. Potential drug–drug interactions with the DAAs are briefly discussed. Furthermore, we summarize what is known about the pharmacodynamics of the DAAs in terms of efficacy and safety. We briefly discuss the relationship between the pharmacokinetics of the DAAs and efficacy or toxicity in special populations, such as hard to cure patients and patients with liver cirrhosis, liver transplantation, renal impairment, hepatitis B virus or HIV co-infection, bleeding disorders, and children. The aim of this overview is to educate/update prescribers and pharmacists so that they are able to safely and effectively treat HCV-infected patients even in the presence of underlying co-infections or co-morbidities. Electronic supplementary material The online version of this article (10.1007/s40262-019-00774-0) contains supplementary material, which is available to authorized users.

BACKGROUND: Cabotegravir and rilpivirine are 2 long-acting (LA) antiretrovirals that can be administered intramuscularly; their interaction with rifampicin, a first-line antituberculosis agent, has not been investigated. The aim of this study was to simulate and predict drug–drug interactions (DDIs) between these LA antiretroviral agents and rifampicin using physiologically based pharmacokinetic (PBPK) modeling. METHODS: The designed PBPK models were qualified (according to European Medicines Agency guidelines) against observed data for oral formulations of cabotegravir, rilpivirine, and rifampicin. Induction potential of rifampicin was also qualified by comparing the DDI between oral cabotegravir and oral rilpivirine with rifampicin. Qualified PBPK models were utilized for pharmacokinetic prediction of DDIs. RESULTS: PBPK models predicted a reduction in both area under the curve (AUC(0-28 days)) and trough concentration (C(trough, 28th day)) of LA cabotegravir of 41%–46% for the first maintenance dose coadministered with 600 mg once-daily oral rifampicin. Rilpivirine concentrations were predicted to decrease by 82% for both AUC(0-28 days) and C(trough, 28th day) following the first maintenance dose when coadministered with rifampicin. CONCLUSIONS: The developed PBPK models predicted the theoretical effect of rifampicin on cabotegravir and rilpivirine LA intramuscular formulations. According to these simulations, it is likely that coadministration of rifampicin with these LA formulations will result in subtherapeutic concentrations of both drugs.

Herbal medication use amongst people living with human immunodeficiency virus (PLWH) is widespread and understudied. This study aimed to evaluate the prevalence of herbal medicine use amongst PLWH and possible contamination with antiretrovirals (ARVs). Countrywide collection of herbal samples sold by street vendors in Nigeria for the following indications: human immunodeficiency virus (HIV), acquired immune deficiency syndrome, fever and general weakness. Samples were screened using a validated liquid chromatography-mass spectrometry/mass spectrometry method for the presence of the following ARVs: efavirenz, nevirapine, lopinavir, darunavir, ritonavir, atazanavir, emtricitabine, tenofovir and lamivudine. A survey was conducted among 742 PLWH attending four HIV clinics in Nigeria. Data were collected using a structured questionnaire and analysed using IBM SPSS statistics version 22.0 (IBM Corp., 2013, Armond, NY). Of the 138 herbal medicines sampled, three (2%) contained detectable levels of tenofovir, emtricitabine and/or lamivudine. Additionally, of the 742 PLWH surveyed, 310 (41.8%) reported herbal medicine use. Among the users, 191 (61.6%) started taking herbals after commencing HIV therapy while herbal medicine use preceded ARVs treatment in 119 (38.4%) PLWH. We found herbal use to be widespread among PLWH in Nigeria, with increasing use after commencing ARV. Three herbal preparations were also found to contain detectable levels of ARVs. This is a concern and should be studied widely across the region and countries where herbal medicine use is prevalent and poorly regulated.

Antiretroviral drugs are among the therapeutic agents with the highest potential for drug–drug interactions (DDIs). In the absence of clinical data, DDIs are mainly predicted based on preclinical data and knowledge of the disposition of individual drugs. Predictions can be challenging, especially when antiretroviral drugs induce and inhibit multiple cytochrome P450 (CYP) isoenzymes simultaneously. This study predicted the magnitude of the DDI between efavirenz, an inducer of CYP3A4 and inhibitor of CYP2C8, and dual CYP3A4/CYP2C8 substrates (repaglinide, montelukast, pioglitazone, paclitaxel) using a physiologically based pharmacokinetic (PBPK) modeling approach integrating concurrent effects on CYPs. In vitro data describing the physicochemical properties, absorption, distribution, metabolism, and elimination of efavirenz and CYP3A4/CYP2C8 substrates as well as the CYP-inducing and -inhibitory potential of efavirenz were obtained from published literature. The data were integrated in a PBPK model developed using mathematical descriptions of molecular, physiological, and anatomical processes defining pharmacokinetics. Plasma drug–concentration profiles were simulated at steady state in virtual individuals for each drug given alone or in combination with efavirenz. The simulated pharmacokinetic parameters of drugs given alone were compared against existing clinical data. The effect of efavirenz on CYP was compared with published DDI data. The predictions indicate that the overall effect of efavirenz on dual CYP3A4/CYP2C8 substrates is induction of metabolism. The magnitude of induction tends to be less pronounced for dual CYP3A4/CYP2C8 substrates with predominant CYP2C8 metabolism. PBPK modeling constitutes a useful mechanistic approach for the quantitative prediction of DDI involving simultaneous inducing or inhibitory effects on multiple CYPs as often encountered with antiretroviral drugs.

A long-acting injectable form of rilpivirine (RPV) is being evaluated in clinical trials for the prevention of HIV infection. Preclinical testing was undertaken to define RPV pharmacokinetic (PK) and pharmacodynamic (PD) activities in ectocervical and colonic tissue treated in vitro . Tenfold dilutions of RPV were added to the basolateral medium of polarized ectocervical and colonic explant tissues. To half the explants, HIV-1 BaL was applied to the apical tissue surface. After culture overnight, all the explants were washed and the RPV in the explants not exposed to HIV was quantified using a validated liquid chromatography-mass spectrometry assay. For efficacy, explants exposed to HIV remained in culture, and supernatants were collected to assess viral replication using a p24 enzyme-linked immunosorbent assay. The data were log 10 transformed, and PK/PD correlations were determined using GraphPad Prism and SigmaPlot software. The application of RPV to the basolateral medium at 10 μM and 1 μM was effective in protecting ectocervical and colonic tissues, respectively, from HIV infection. When the RPV in paired ectocervical and colonic explant tissues was quantified, significant inverse linear correlations ( P < 0.001) between p24 and RPV concentrations were obtained; more viral replication was noted at lower drug levels. Using a maximum effect model, RPV concentrations of 271 nM in ectocervical tissue and 45 nM in colonic tissue were needed to achieve a 90% effective concentration (EC 90 ). These data demonstrate that RPV can suppress HIV infection in mucosal tissue but that higher levels of RPV are needed in female genital tract tissue than in gastrointestinal tract tissue for protection.

Women receiving efavirenz-based antiretroviral therapy plus a contraceptive implant had significantly lower levonorgestrel pharmacokinetics than women not receiving antiretroviral therapy. An unexpected high pregnancy rate (3/20, 15%) occurred in the efavirenz group, highlighting the clinical significance of this interaction., Background. Levonorgestrel subdermal implants are preferred contraceptives with an expected failure rate of

International audience; Ombitasvir/paritaprevir/ritonavir ± dasabuvir ± ribavirin (OBV/PTV/r ± DSV ± RBV) regimens show high efficacy and good tolerability in clinical trials for chronic hepatitis C virus (HCV) genotypes (GT) 1 or 4. To evaluate whether these results translate to clinical practice, data were pooled from observational studies across 13 countries. Treatment‐naïve or ‐experienced patients, with or without cirrhosis, received OBV/PTV/r ± DSV ± RBV according to approved local labels and clinical practice. Sustained virologic response at post‐treatment Week 12 (SVR12), adverse events (AEs) and comedication management were assessed for patients initiating treatment before 1 June 2017. The safety population included 3850 patients who received ≥1 dose of study drug. The core population (N = 3808) further excluded patients with unknown GT or cirrhosis status, or who received off‐label treatment. Patients had HCV GT1a (n = 732; 19%), GT1b (n = 2619; 69%) or GT4 (n = 457; 12%). In 3546 patients with sufficient follow‐up data at post‐treatment Week 12, the SVR12 rate was 96% (n/N = 3401/3546 [95% CI 95.2‐96.5]). In patients with or without cirrhosis, SVR12 was comparable (96%). In patients with HCV GT1a, GT1b or GT4, SVR12 rates were 93%, 97% and 94%. In GT1b‐infected patients with planned treatment for 8 weeks, SVR12 was 96%. In patients with ≥1 comorbidity (67%), SVR12 was 95%. 58% of patients received ≥1 comedication, and there was minimal impact on SVR12 rates using comedications for peptic ulcers and gastro‐esophageal reflux disease, statins, antipsychotics or antiepileptics. Most comedications were maintained during treatment although 58% of patients changed their statin medication. AEs and serious AEs occurred in 26% and 3% of patients. Post‐baseline Grade 3‐4 laboratory abnormalities were rare (

Background:Antiretroviral therapy in HIV-positive patients leads to insulin resistance which is central to the pathogenesis of various metabolic abnormalities and cardiovascular disease seen in this patient group. We have investigated the dose–response relationship of telmisartan, an antihypertensive, on adipocytes in vitro in order to determine whether it may have metabolic beneficial effects.Methods:Using in vitro chronic toxicity models (3T3-F442A murine and primary human adipocytes), we evaluated the effects of different concentrations of telmisartan on adipocyte differentiation and adipogenic gene expression using lipid accumulation assays and real-time polymerase chain reaction, respectively. Adipokine secretion and expression of insulin signalling mediators were evaluated using enzyme-linked immunosorbent assays.Results:Telmisartan partially reversed the deleterious effects of antiretrovirals on adipocyte lipid accumulation, expression of adipogenic regulators (peroxisome proliferator receptor-gamma and lipin 1), adipokine secretion and expression of the insulin signalling mediator pAktSer473. The metabolic effects of telmisartan followed a non-monotonic response with the maximal effect observed at 5 µM in the primary human adipocyte model.Conclusion:Telmisartan has beneficial metabolic effects in adipocytes in vitro, but its potential to reduce antiretroviral-induced cardiometabolic disease in HIV-infected individuals needs to be evaluated in a well-designed adequately powered clinical trial.

Background HIV-positive women receiving efavirenz-based ART and levonorgestrel contraceptive implants are at risk of low levonorgestrel exposure and unintended pregnancy. Objectives To investigate clinically applicable dose-adjustment strategies to overcome the known drug-drug interaction (DDI) between levonorgestrel and efavirenz, using a physiologically based pharmacokinetic (PBPK) modelling-based approach. Methods A PBPK model was qualified against clinical data to predict levonorgestrel plasma concentrations when standard-dose (150 mg) levonorgestrel implants were administered alone (control group), as well as when standard-dose or increased-dose (300 mg) levonorgestrel implants were coadministered with either 600 or 400 mg of efavirenz. Results No difference was seen between in vivo clinical and PBPK-model-simulated levonorgestrel plasma concentrations (P > 0.05). Simulated levonorgestrel plasma concentrations were ∼50% lower at 48 weeks post-implant-placement in virtual individuals receiving standard-dose levonorgestrel with either 600 or 400 mg of efavirenz compared with the control group (efavirenz:control geometric mean ratio = 0.42 and 0.49, respectively). Conversely, increased-dose levonorgestrel in combination with either 600 or 400 mg of efavirenz was sufficient to restore levonorgestrel concentrations to levels similar to those observed in the 150 mg levonorgestrel control group 48 weeks post-implant-placement (efavirenz:control geometric mean ratio = 0.86 and 1.03, respectively). Conclusions These results suggest that the clinically significant DDI between efavirenz and levonorgestrel is likely to persist despite efavirenz dose reduction, whereas dose escalation of implantable levonorgestrel may represent a successful clinical strategy to circumvent efavirenz-levonorgestrel DDIs and will be of use to inform clinical trial design to assess coadministration of efavirenz and levonorgestrel implants.

Levonorgestrel (LNG) is a synthetic progestin that is available in oral contraceptive tablets, a subdermal implant, and an intrauterine system for contraception. LNG pharmacokinetics are a pivotal determinant of contraceptive efficacy and essential in assessing drug-drug interactions influencing LNG exposure following different routes of LNG administration. A highly sensitive LC-MS/MS method was developed and validated to quantify levonorgestrel in human plasma. Liquid-liquid extraction was utilized with a sample volume of 500 μL to extract levonorgestrel from plasma. Chromatographic separation of LNG was achieved with a Fortis™ C18 (3 μm: 100mm × 2.1mm) reverse phase analytical column. The mobile phases consisted of de-ionized water plus 0.1% NH(4)OH (100:0.1%, v/v) (A), and methanol plus 0.1% NH(4)OH (100:0.1%, v/v) (B) delivered as a gradient at a flow rate of 400 μL/min. Detection of LNG and internal standard (D-(-)-norgestrel-d7) was achieved using positive polarity mode monitoring at 313.2-245.2 amu and 320.1-251.2 amu, respectively. The assay was linear over the calibration range of 49.6 to 1500 pg/mL. This method was used to quantify plasma LNG released by subdermal implant in support of a drug interaction study among women with HIV receiving efavirenz- or nevirapine-based antiretroviral therapy.

We aimed at investigating the antiviral activity and the pharmacokinetics of the dual antiretroviral (ARV) combination of rilpivirine plus darunavir/ritonavir 25/800/100 mg once-daily in naïve HIV-1-infected individuals (NHII) with different baseline viral loads.Pharmacokinetic/pharmacodynamics study in ARV-naïve HIV-infected individuals.The primary endpoint was the number of NHII with HIV-RNA 40 copies/mL at week 48. Secondary endpoints included rilpivirine/darunavir/ritonavir pharmacokinetics, HIV-RNA decay, and changes in ECG QT interval.Thirty-six individuals were enrolled, 18 with a baseline viral load 100,000 copies/mL (group A) and 18 with a baseline viral load 100,000 copies/mL (group B). All but 1 (HIV-RNA = 63 copies/mL) subjects achieved viral load 50 copies/mL by week 36, and all at week 48. Median (range) HIV-RNA reduction (Log10 copies/mL) was 1.3 (0.6-1.9) over the first week, with no differences between groups A and B. Geometric mean and 95%CI rilpivirine Crilpivirine/darunavir/ritonavir could be efficacious, with limited short-term toxicity in ARV-naïve patients. Although rilpivirine was co-administered with ritonavir, its exposure was within ranges measured during phase III trials.

Objective Maraviroc (MVC) is a potential candidate for 'on demand' preexposure prophylaxis. In the present study, we evaluated the efficacy of a single oral dose of MVC to prevent ex-vivo HIV-1 infection of rectal tissue in humans. Design and methods Eight HIV-1-negative healthy volunteers received a single oral dose of MVC (300 or 600 mg), and two additional volunteers received tenofovir disoproxil fumarate/emtricitabine (TDF/FTC, 300/200 mg) for 10 days. Rectal biopsies were performed prior to the ex-vivo challenge (day 0), at day 7 (4 h after MVC) or after 10 days with TDF/FTC. Rectal biopsies were infected ex-vivo, and viral inhibition and CCR5 occupancy was analyzed. MVC concentration in plasma and rectal tissue was measured just after biopsy and after viral incubation. Results Ex-vivo rectal tissue protection with MVC was incomplete in all but two participants, whereas TDF/FTC avoided ex-vivo infection in the two controls. Median dose-normalized concentration of MVC was significantly higher in rectal tissue than in plasma (561.1 and 155.1 ng/ml, respectively). A significant loss of MVC during the virus incubation (about 60%) and a low CCR5 occupancy (approximately 45%) were detected in rectal cells. Conclusions An ex-vivo challenge with a single oral dose of MVC does not prevent ex-vivo infection of human rectal mucosa. The lack of prophylactic efficacy observed suggests that 'on demand' MVC preexposure prophylaxis would not prevent rectal HIV-1 transmission.

Pharmacokinetic (PK) data describing a prolonged time course of antiretrovirals in plasma and peripheral blood mononuclear cells (PBMCs) are important for understanding and managing late or missed doses and to assess the appropriateness of compounds for preexposure prophylaxis (PrEP). This study aimed to evaluate the PK of coformulated tenofovir disoproxil fumarate (DF), emtricitabine, and rilpivirine in plasma and of the intracellular (IC) anabolites tenofovir diphosphate (TFV-DP) and emtricitabine triphosphate (FTC-TP) in healthy volunteers up to 9 days after drug cessation. Individuals received daily tenofovir DF-emtricitabine-rilpivirine (245/200/25 mg) for 14 days. Drug intake was stopped, and serial sampling occurred prior to the final dose and up to 216 h (9 days) after stopping drug intake. Concentrations were quantified and PK parameters calculated. Eighteen volunteers completed the study. The terminal elimination plasma half-lives for tenofovir and emtricitabine over 216 h (geometric mean [90% confidence interval]) were higher than those seen over 0 to 24 h (for tenofovir, 31 h [27 to 40 h] versus 13.3 h [12.5 to 15.1 h]; for emtricitabine, 41 h [36 to 54 h] versus 6.4 h (5.9 to 7.6 h]). Model-predicted IC half-lives (0 to 168 h) were 116 h (TFV-DP) and 37 h (FTC-TP). The plasma rilpivirine concentration at 216 h was 4.5 ng/ml (4.2 to 6.2 ng/ml), and half-lives over 0 to 216 h and 0 to 24 h were 47 h (41 to 59 h) and 35 h (28 to 46 h), respectively. These data contribute to our understanding of drug behavior following treatment interruption; however, adherence to therapy should be promoted. Validated plasma and IC target concentrations are necessary to allow interpretation with respect to sustained virus suppression or HIV prevention. (The trial was conducted in accordance with the Declaration of Helsinki [EudraCT 2012-002781-13].)

Use of 'party drugs', a particular set of recreational drugs used in the context of 'ChemSex', is frequent among MSM living with HIV. A recently published observational study showed that more than half of HIV-infected MSM interviewed reported use of illicit substances in the previous 3 months, with frequent concomitant use of three or more drugs. These substances are a combination of 'club drugs' (methylenedioxymethamphetamine, gamma-hydroxybutyrate, ketamine, benzodiazepine) and drugs that are more specifically used in a sexualized context (methamphetamine, mephedrone, poppers and erectile dysfunction agents). Although formal data on pharmacokinetic or pharmacodynamic interactions between recreational drugs and antiretroviral agents are lacking, information regarding potentially toxic interactions can be theorized or sometimes conclusions may be drawn from case studies and cohort observational studies. However, the risk of coadministering party drugs and antiretrovirals should not be overestimated. The major risk for a drug-drug interaction is when using ritonavir-boosting or cobicistat-boosting agents, and maybe some nonnucleoside reverse transcriptase inhibitors. Knowledge of the metabolic pathways of 'party drugs' may help in advising patients on which illicit substances have a high potential for drug-drug interactions, as this is not the case for all.

Objectives The validation and clinical application of an LC-MS/MS method for the quantification of nevirapine in dried blood spots (DBS) and dried breast-milk spots (DBMS) are presented. Methods DBS and DBMS were prepared from 50 and 30 μL of nevirapine-spiked whole blood and human breast milk, respectively. Chromatographic separation was achieved on a reverse-phase C18 column with 0.1% formic acid in water/acetonitrile using a solvent gradient programme at a flow rate of 400 μL/min, and detection was by a TSQ Quantum Access triple quadrupole mass spectrometer. The clinical application was evaluated in HIV-positive nursing mothers and their breastfed infants. Results The assay was validated over the concentration range 50-10,000 ng/mL. Accuracy ranged from 93.3% to 113.4% and precision ranged from 1.9% to 12.0%. The mean (percentage coefficient of variation) recovery of nevirapine from DBS and DBMS was ≥ 70.7% (≤ 8.2) and the matrix effect was ≤ 1.04 (≤ 6.1). Nevirapine was stable in DBS and DBMS for ≥ 15 months at room temperature and -80°C. Mean (SD) AUC0-12, Cmax and Cmin in maternal plasma versus breast milk were 57,808 ng · h/mL (24,315) versus 55,817 ng · h/mL (22,368), 6140 ng/mL (2605) versus 5231 ng/mL (2215) and 4334 ng/mL (1880) versus 4342 ng/mL (2245), respectively. The milk-to-plasma concentration ratio over the dosing interval was 0.94 (0.15). Infant plasma concentrations 2 and 8 h after maternal dosing were 580.6 ng/mL (464.7-1607) and 584.1 ng/mL (381.5-1570), respectively. Conclusions These methods further extend opportunities for conducting clinical pharmacokinetic studies in nursing mother-infant pairs, especially in resource-limited settings.

Antiretrovirals are currently used for the treatment and prevention of HIV infection. However, poor adherence and low tolerability of some existing oral formulations can hinder their efficacy. Long-acting (LA) injectable nanoformulations could help address these complications by simplifying antiretroviral administration. The aim of this study is to inform the optimisation of intramuscular LA formulations for eight antiretrovirals through physiologically based pharmacokinetic (PBPK) modelling.A whole-body PBPK model was constructed using mathematical descriptions of molecular, physiological and anatomical processes defining pharmacokinetics. These models were validated against available clinical data and subsequently used to predict the pharmacokinetics of injectable LA formulationsThe predictions suggest that monthly intramuscular injections are possible for dolutegravir, efavirenz, emtricitabine, raltegravir, rilpivirine and tenofovir provided that technological challenges to control their release rate can be addressed.These data may help inform the target product profiles for LA antiretroviral reformulation strategies.

Aims Direct‐acting antiviral agents (DAAs) for the treatment of hepatitis C (HCV) can be associated with drug–drug interactions (DDIs) with concomitant medications. The practical clinical implications of such DDIs are poorly understood. We assessed the clinical impact of possible pharmacokinetic (PK) interactions between simeprevir and frequently prescribed concomitant medications. Methods This post hoc analysis pooled data from nine studies which evaluated simeprevir (SMV)‐based interferon‐free HCV treatment. Three classes of frequently used concomitant medications of interest (CMOIs) were analysed [antihypertensive drugs (AHDs), anxiolytic drugs (AXDs) and lipid‐lowering drugs (LLDs)] and categorized as amber or green according to their DDI potential with SMV (green: no DDIs; amber: potential/known PK interactions). Concomitant medications not recommended to be coadministered with SMV were not included. The composite primary endpoint was defined as the frequency of either discontinuation, interruption or dose modification of the CMOI during 12 weeks of SMV treatment. Results Few patients met the composite endpoint in the various subgroups. Patients on amber CMOIs tended to experience CMOI modification more often (13.4–19.4%) than those on green CMOIs (3.1–10.8%). There was no difference in the frequency of adverse events between patients taking green and those taking amber CMOIs. Conclusions In this large pooled analysis, coadministration of the evaluated commonly prescribed medications with known or potential PK interactions with SMV was manageable and resulted in few adjustments of concomitant medications. Our method could serve as a blueprint for the evaluation of the impact of DDIs.

The prevalence of HIV-infected people aged 50 years or older is increasing rapidly; the proportion will increase from 28% to 73% in 2030. In addition, HIV-infected individuals may be more vulnerable to age-related condition. There is growing evidence that the prevalence of comorbidities and other age-related conditions (geriatric syndromes, functional or neurocognitive/mental problems, polypharmacy, and social difficulties) is higher in the HIV-infected population than in their uninfected counterparts. However, despite the potential impact of this situation on health care, little information exists about the optimal clinical management of older HIV-infected people. Here we examine the age-related conditions in older HIV-infected persons and address clinical management according to author expertise and published literature. Our aim is to advance the debate about the most appropriate management of this population, including less well-studied aspects, such as frequency of screening for psychological/mental and social and functional capabilities.