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Ruxolitinib is an FDA-approved orally administered Janus kinase (JAK 1/2) inhibitor that reduces cytokine-induced inflammation. As part of a randomized, Phase 2, open label trial, ruxolitinib (10 mg, bid) was administered to HIV(+), virologically suppressed individuals (33 men, 7 women) on antiretroviral therapy (ART), for 5 weeks. Study objectives were to assess safety, tolerability, pharmacokinetics (PK), and modulation of ongoing inflammation that persists even with viral suppression. Herein, we report the population PK subsequently determined from this study. Plasma concentrations of ruxolitinib (294 samples) and antiretroviral agents were measured at week 1 (wk1, N = 39 participants) and week 4 or 5 (wk4/5, N = 37). Ruxolitinib PK was adequately described with a 2-compartment model with first-order absorption and elimination with distribution volumes normalized to mean body weight (91.5 kg) and a separate typical CL for participants administered efavirenz (a known CYP3A4 inducer). Participants administered an ART regimen with efavirenz had an elevated typical CL/F versus the integrase inhibitor regimen (INSTI) group (22.5 versus 12.9 L/hr; N = 14 versus 25). Post hoc predicted CL/F were likewise, more variable and higher (p < 0.0001) in those administered efavirenz. There was ~ 25% variation in ruxolitinib plasma exposures between wk1 and wk4/5. ART plasma concentrations resembled those from PK studies without ruxolitinib. Therefore, INSTI based ART regimens may be preferred over efavirenz based regimens when ruxolitinib is administered to HIV(+) individuals.

The antiretroviral protease inhibitor atazanavir inhibits hepatic uridine diphosphate glucuronosyltransferase (UGT) 1A1, thereby preventing the glucuronidation and elimination of bilirubin. Resultant indirect hyperbilirubinemia with jaundice can cause premature discontinuation of atazanavir. Risk for bilirubin-related discontinuation is highest among individuals who carry two UGT1A1 decreased function alleles (UGT1A1*28 or *37). We summarize published literature that supports this association and provide recommendations for atazanavir prescribing when UGT1A1 genotype is known (updates at www.pharmgkb.org).

Despite highly active antiretroviral therapy (HAART), human immunodeficiency virus-1 (HIV-1) continues to elude eradication. Even in the setting of plasma virologic suppression, HIV-1 RNA can be found in peripheral blood mononuclear cells (PBMCs), genital secretions, gastrointestinal lymphoid tissue, and cerebrospinal fluid (CSF).1,2 Limited penetration of antiretrovirals (ARVs) into these sites may play a role in viral persistence.2,3 HIV-1 invades the central nervous system (CNS) early after infection via macrophages, monocytes, and dendritic cells.4 Over time, HIV-associated neurocognitive disorders (HAND) can develop,5 contributing significantly to morbidity6 and early mortality.7 While severity of HAND has decreased, prevalence remains unchanged since the pre-HAART era: 36.2–44.8%,6 prompting a concern for suboptimal CNS control of HIV. This is supported by reports of elevated neopterin, an inflammatory biomarker, and measurable HIV RNA in the CSF of patients on long term HAART,8,9 both predictive markers for development of HIV-associated dementia.10,11 Some studies suggest that limited CNS penetration by ARVs is associated with HAND.12,13 Molecular size, lipophilicity, affinity for efflux pump transporters, and degree of plasma protein binding are factors that impact drug CNS penetration.14 Lipophilic drugs, including HIV protease inhibitors (PIs), are highly bound to plasma protein, predominantly alpha1-acid glycoprotein (AAG). The plasma unbound (free) drug component is considered pharmacologically active and readily crosses the blood–brain and blood–CSF barriers15,16 therefore highly bound drugs such as PIs may have limited CNS penetration. Two PIs, atazanavir (ATV) and darunavir (DRV), are recommended by the Department of Health and Human Services (DHHS) as part of first-line once daily regimens for ARV-naive patients when boosted with ritonavir (RTV) and given with a backbone of tenofovir disoproxil fumarate/emtricitabine (TDF/FTC).17 Both PIs have characteristics that could impede tissue and CNS penetration, including large molecular size and affinity for efflux pump transporters. However, they differ in their affinity for plasma AAG: ATV is 86% plasma protein bound in vitro whereas DRV is 95% bound.18,19 The degree to which they successfully penetrate the CNS remains unclear. Best et al showed low or undetectable CSF ATV levels in nearly 25% of study participants.20 but measured only total drug concentrations with a lower quantitation limit of 5 ng/mL. In contrast, 3 prior studies have shown that DRV can attain drug concentrations in the CSF exceeding IC50 21–23 ; however, the single study measuring unbound drug concentrations22 examined participants receiving twice daily DRV rather than the DHHS recommended once daily dosing schedule for patients without history of DRV resistance.17 Additionally, measuring random total drug concentrations rather than troughs limited all previous studies. To address these limitations, we evaluated the CSF penetration of once daily DRV relative to ATV, both boosted with RTV and administered with the same background TDF/FTC regimen. We hypothesized that ATV, a PI with lower degree of plasma protein binding, would achieve a higher CSF/plasma unbound drug concentration ratio than DRV. In addition, we compared unbound CSF PI concentrations to their drug-specific IC50 and assessed relationships with CSF HIV-1 RNA and neopterin.

J Oral Pathol Med (2012) 41: 288–291 Background: Oral human papillomavirus (HPV) is associated with several health complications especially in combination with HIV infections. Screening may be useful, but methodologies and results have varied widely in previous studies. We conducted a pilot study in an HIV-positive population to evaluate HPV detection in four different oral sample types. Methods: Upon enrollment, an oral-rinse (OR) sample was collected in 10 ml saline. Additional samples of the buccal mucosa, tonsils, and oral lesion if present were collected with cytology brushes. DNA was extracted using LC-MagNAPure, and the Linear Array HPV genotyping Assay (Roche) was used for HPV genotyping. Results: In samples from 100 HIV-positive participants, HPV was detected in 39 (%) of the oral rinses, 13 (%) mucosal and 11 (12.9%) tonsil brushings. Of seven lesion brushings collected, four were HPV positive. All participants with HPV detected in mucosal, tonsil, or lesion brushings were also positive in the OR sample. Among the rinse samples, 27 different genotypes were detected with HPV84 (n = 6), HPV55 (n = 5), and HPV83 (n = 5) being the most common. Multiple infections were detected in 17 samples (range 2–9, mean 1.9 types). As potential cofactors, only receptive oral sex was significantly associated with HPV (P = 0.018, odds ratio 2.9, 95% CI 1.2–6.9). Conclusion: Sampling is a significant factor for oral prevalence studies. Oral rinse provides the best representation for HPV in the oral cavity. To evaluate associated cofactors other than receptive oral sex, larger studies with case–control design are necessary.

Constructing an effective therapeutic regimen for antiretroviral-experienced patients with persistent viremia despite ongoing therapy is a nagging challenge in the management of human immunodeficiency virus (HIV) infection. Although several new classes of antiretroviral agents with activities against multidrug-resistant HIV-1 viral strains are in the developmental pipeline, the antiviral activities of these newer drugs are optimal in the presence of an active background antiretroviral therapy.1, 2 Therefore, the need exists to continue to identify combinations of agents among currently approved antiretroviral drugs that are pharmacokinetically compatible, safe, and potentially active against multidrug-resistant HIV strains. Ritonavir-boosted dual–protease inhibitor regimens are used as a component of a salvage combination therapy.3-6 By inhibiting the cytochrome P450 (CYP) 3A4 isoenzyme, ritonavir enhances the pharmacokinetics of protease inhibitors to levels that could produce sustained virologic suppression for viral strains with moderate phenotypic resistance similar to ritonavir pharmacoenhancement in the naive setting.7, 8 Furthermore, pharmacoenhancement of two or more active protease inhibitors with nonoverlapping resistance mutation patterns may result in a higher genetic barrier to resistance and possibly synergistic activity against HIV. For these reasons, a ritonavir-enhanced indinavir-amprenavir combination appears attractive for salvage therapy in HIV infection. Fosamprenavir, a prodrug of amprenavir, is rapidly hydrolyzed to its parent form by cellular phosphatases in the gut epithelium during absorption.9 Not only are the plasma concentrations of indinavir and amprenavir enhanced by ritonavir,10 the two agents have nonoverlapping primary resistance patterns.11, 12 However, our knowledge of limiting drug-drug interactions that occur with a number of boosted double–protease inhibitor combinations13-15 makes it essential to evaluate the pharmacokinetics of these regimens before their clinical use. In this study, we evaluated the pharmacokinetic interaction of a ritonavir-boosted indinavir-fosamprenavir combination among HIV-infected patients. If pharmacokinetically compatible, a ritonavir-boosted indinavir-fosamprenavir regimen could be a suitable adjunct in salvage therapy of highly treatment-experienced HIV-infected patients with multidrug-resistant viruses.

The aim of this study was to determine the impact of sex on the pharmacokinetics of lopinavir/ritonavir. Interaction between lopinavir/ritonavir and tenofovir was also evaluated. Steady-state plasma samples were obtained from virologically suppressed HIV-infected patients on lopinavir/ritonavir 800/200-mg soft gel capsule taken once daily. Drug assays were performed by high-performance liquid chromatography. Pharmacokinetic parameters estimated by noncompartmental method were reported as 90% confidence intervals (CIs) about the geometric mean ratio (GMR). There were 9 males and 11 females. No sex differences were observed in lopinavir/ritonavir pharmacokinetics profile. The GMR(sex) (women compared with men) for lopinavir area under the concentration-time curve (AUC(24)), maximum concentration (C(max)), and minimum concentration (C(min)) was 0.95 (90% CI, 0.70-1.29), 0.88 (90% CI, 0.67-1.15), and 1.27 (90% CI, 0.60-2.66), respectively. Similarly, the GMR(sex) for ritonavir AUC(24), C(max), and C(min) was 0.84 (90% CI, 0.57-1.24), 0.79 (90% CI, 0.50-1.22), and 1.02 (90% CI, 0.58-1.80), respectively. Tenofovir coadministration led to a reduction in lopinavir/ritonavir plasma exposure, giving a lopinavir GMR(tenofovir) for C(max) of 0.72 (90% CI, 0.57-0.93) and AUC(24) of 0.74 (90% CI, 0.56-0.98), respectively. No difference in lopinavir/ritonavir plasma concentrations between sexes was demonstrated in this study. However, tenofovir coadministration lowered lopinavir/ritonavir plasma exposure.