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Objective: Elvitegravir (EVG) is in phase 3 development in combination with ritonavir (RTV)-boosted protease inhibitors in treatment-experienced, HIV-infected patients. Two studies evaluated pharmacokinetic (PK) interactions among EVG and RTV-boosted tipranavir (TPV/r) or darunavir (DRV/r)., Methods: Healthy volunteers received EVG/r alone (study 1: 200/100 mg once daily; study 2: 125/100 mg once daily), TPV/r (500/200 mg twice daily) or DRV/r (600/100 mg twice daily) alone, and EVG (200 or 125 mg as applicable) added to TPV/r (500/200 mg twice daily) or DRV/r (600/100 mg twice daily) in a randomized crossover design, with assessment of steady-state PK for EVG, TPV, DRV, and RTV. Safety was assessed by clinical monitoring. Studies were powered to conclude lack of an interaction if the 90% confidence interval for the geometric mean ratios of the AUCtau and Cmax for EVG, TPV, and DRV were within predefined no-effect boundaries. Trough concentrations were also assessed., Results: No subjects discontinued for adverse events during treatment with EVG/r alone. On coadministration, AUCtau and Cmax of EVG and TPV and EVG and DRV were within prespecified no-effect boundaries versus treatment alone; trough concentrations were also not substantially altered., Conclusions: The PK of EVG and TPV or DRV were not altered after coadministration of EVG with TPV/r or DRV/r. EVG PK was similar with varied RTV doses of 100 mg once daily, 100 mg twice daily, or 200 mg twice daily. EVG can be added to TPV/r or DRV/r regimens without dose adjustment.

Background: Antiretroviral tolerability is a critical factor contributing to treatment outcome. The T-20 Versus Optimized Background Regimen Only (TORO) studies assessed the safety and efficacy of enfuvirtide in treatment-experienced HIV-1-infected patients., Methods: A total of 997 patients were randomized at a 2:1 ratio to an optimized background antiretroviral regimen plus enfuvirtide (n = 663) or an optimized background regimen alone (control group; n = 334). Control patients could switch to enfuvirtide on virologic failure., Results: In total, 26.5% of patients randomized to enfuvirtide and 36.6% to the control group discontinued study treatment before week 48; the percentage of patients withdrawn for safety reasons (including adverse events [AEs], deaths, and laboratory abnormalities) was 14.0% in the enfuvirtide group and 11.6% in the control group. Injection site reactions (ISRs) occurred in 98% of enfuvirtide patients and led to treatment discontinuation in 4.4%. Treatment-related (defined as possibly, probably, or remotely) AE rates per 100 patient-years were lower with enfuvirtide (96.2) than in the control group (149.9); diarrhea, nausea, and fatigue, the most frequently reported AEs, were significantly less frequent with enfuvirtide than in the control group. Pneumonia was significantly more frequent in patients treated with enfuvirtide (6.7 vs. 0.6 events per 100 patient-years), although the incidence was within expected ranges for this population. Lymphadenopathy was also higher in enfuvirtide-treated patients (7.1 vs. 1.2 events per 100 patient-years) for control patients., Conclusion: The addition of enfuvirtide to an optimized background regimen does not exacerbate AEs commonly associated with antiretrovirals. ISRs limited treatment in <5% of patients.

Background: The T-20 Versus Optimized Background Regimen Only (TORO) 1 and TORO 2 clinical trials are open-label, controlled, parallel-group, phase 3 studies comparing enfuvirtide plus an optimized background (OB) of antiretrovirals (n = 661) with OB alone (n = 334) in treatment-experienced HIV-1-infected patients., Methods: The primary objective at week 48 was to investigate durability of efficacy, as measured by the percentage of patients maintaining their week 24 response or improving. Efficacy analyses used the intent-to-treat population., Results: A total of 73.7% of patients randomized to the enfuvirtide group remained on treatment through week 48 versus 21.3% originally randomized to the control group. At week 48, a higher proportion of week 24 responders maintained their response or were new responders in the enfuvirtide group than in the control group in each responder category: HIV-1 RNA level > or =1.0 log(10) change from baseline, <400 copies/mL and <50 copies/mL (37.4%, 30.4%, and 18.3% in the enfuvirtide group vs. 17.1%, 12.0%, and 7.8% in the control group, respectively; P < 0.0001 for all comparisons). CD4 cell count increases from baseline were twice as great in the enfuvirtide group as in the control group., Conclusion: These data demonstrate durable efficacy of enfuvirtide plus OB over 48 weeks.

The current primary goal of therapy for HIV-1 infection is suppression of viral replication to below detectable levels (less than 50 copies/mL). The most important challenge facing current HIV-1 research is designing agents that prevent the emergence of or overcome drug-resistant HIV-1 variants. Shortcomings of antiretroviral therapy have sparked interest in immunologic enhancement through vaccines and immunomodulators, specifically antigen stimulation, induction of HIV-1 specific memory and cytotoxic T-cell responses, and activation of resting CD4+ cells within latent HIV-1 reservoirs. New classes of antiretroviral agents include entry inhibitors and nucleotide reverse transcriptase inhibitors. This article discusses the status of successful HIV treatment strategies, including new treatment practices, antiretroviral agents, and immune-enhancing agents.

Atazanavir (formerly BMS-232632), an azapeptide protease inhibitor (PI), is a new human immunodeficiency virus (HIV) treatment that has recently received marketing approval from the FDA. It has a pharmacokinetic profile that supports once-daily dosing and has demonstrated a unique resistance profile and superior virologic potency compared with other antiretrovirals in vitro. In subjects with HIV, atazanavir (400 mg once daily) produced rapid and sustained improvements in viral load and CD4 counts in both antiretroviral-naive as well as previously treated patients when used in combination with dual nucleoside reverse transcriptase inhibitor (NRTI) treatment. In these studies atazanavir demonstrated comparable anti-HIV efficacy to nelfinavir (twice or three times daily), efavirenz and the combination of ritonavir and saquinavir. However, unlike these comparator agents, atazanavir did not adversely affect the plasma lipid profile, an advantage that sets it apart from other currently available PIs. Atazanavir was inferior to lopinavir/ritonavir in patients who previously failed an initial protease inhibitor containing regimen. Preliminary results in multiple PI-experienced patients indicate comparable efficacy to lopinavir/ritonavir in subjects receiving a boosted regimen of atazanavir plus ritonavir. In summary, atazanavir offers several therapeutic advantages, including a convenient once-daily dosing schedule, neutral lipid effects and a distinct resistance profile. These characteristics may ultimately help improve adherence, reduce the potential risk of long-term cardiovascular events associated with dyslipidemia, and increase the range of therapeutic options available for patients failing other antiretroviral regimens.

The advent of HAART has improved survival in patients infected with HIV; however, treatment is complicated by potential drug interactions. The risk of drug interactions is compounded by the use of additional therapies for comorbid conditions, such as substance abuse, and by the use of recreational drugs. HIV health care providers should be aware of the potential interaction of recreational drugs and addiction treatments with HAART because of the potential for significant adverse effects for their HIV-infected patients. This article provides a review of the literature on drug interactions among addiction therapies, recreational drugs, and HAART.

Objective: Dyslipidemia and other metabolic abnormalities, which are associated with the use of highly active antiretroviral therapy (HAART) for the treatment of HIV infection, are of concern to patients and healthcare providers. The objective of this review is to present the current understanding of the dyslipidemia associated with the protease inhibitor (PI)-component of HAART: its possible origin, potential consequences, and management techniques., Data Sources, Study Selection: Peer-reviewed, published literature was identified via MEDLINE. Other sources included abstracts from recent HIV-related conferences that presented data pertinent to the topic. Studies were selected based on their impact on our understanding of HIV infection and its treatment., Data Extraction, Synthesis: Relevant portions of the publications considered were compiled and conclusions were drawn based on the clinical experience of the author., Conclusion: Dyslipidemia associated with current PIs should be a serious consideration when initiating long-term treatment of HIV infection. Current management techniques that include lipid-lowering agents may be improved and streamlined by incorporating a lipid-friendly PI into HAART.

Coinfection with HIV and hepatitis B virus (HBV) is more common than that with HIV and hepatitis C virus (HCV), although more attention has been given to HCV coinfection as a result of its higher frequency of chronic disease. Natural history studies with HIV-HCV coinfection have also shown more rapid progression of liver disease, and end-stage liver disease due to hepatitis C is now a leading cause of death in HIV-infected patients. Like HCV infection, HBV infection can also be associated with significant morbidity and mortality in patients with HIV infection. Fortunately, treatment options of hepatitis B are expanding and may have a clinical impact on slowing disease progression. A case study of a patient with severe HBV-HIV coinfection is presented to illustrate what is known about this increasingly problematic disease state.