Biomedical subjects

Joel Gallant

Publications and source records attributed to Joel Gallant.

4 recordsLinked to original sources

PubMed2003

A phase I/II study of nevirapine for pre-exposure prophylaxis of HIV-1 transmission in uninfected subjects at high risk.

OBJECTIVE: To evaluate the safety, tolerability, and trough levels of three pre-exposure prophylaxis regimens of nevirapine among HIV-1-uninfected subjects at high risk for HIV-1 infection. METHODS: A phase I/II trial (HIVHOP 101) in which 33 such uninfected subjects received a 200 mg tablet of nevirapine once weekly (cohort A, n = 12), twice weekly (cohort B, n = 12), or every other day (cohort C, n = 9) for 12 weeks. Clinical signs/symptoms, laboratory parameters, and nevirapine trough levels were assessed at entry and at 1, 2, 4, 6, 9, and 12 weeks, with a follow-up sample at 16 weeks. RESULTS: No subject experienced clinical symptoms attributed to nevirapine, including rash. There were no significant changes in liver enzyme levels from baseline to week 12 in the three cohorts, except for glutamyl transpeptidase in cohort B. Median nevirapine trough levels at weeks 1 and 12 were 119 ng/ml (range, < 25-205) and 135 ng/ml (range, < 25-1065), respectively, for cohort A, 569 ng/ml (range, 135-2641) and 431 ng/ml (range, 42-2454) for cohort B, and 1942 ng/ml (range, 1214-2482) and 943 ng/ml (range, 262-5281) for cohort C. No subject became HIV-1 antibody positive by week 16. CONCLUSIONS: A single dose of nevirapine taken once weekly, twice weekly, or every other day for 12 weeks was safely tolerated by the subjects in this small study, and resulted in nevirapine levels well above the IC (inhibitory concentration of 50%: 10 ng/ml) over the 12-week period in nearly all evaluable subjects. (50)

Anti-HIV Agents↗

PubMed2003

Tipranavir.

Explore the source record for details and available documents.

Clinical Trials as Topic↗

PubMed2002

Virtual inhibitory quotient predicts response to ritonavir boosting of indinavir-based therapy in human immunodeficiency virus-infected patients with ongoing viremia.

Depending on the degree of underlying resistance present, optimization of the pharmacokinetics of protease inhibitors may result in improved virologic suppression. Thirty-seven human immunodeficiency virus (HIV)-infected subjects who had chronic detectable viremia and who were receiving 800 mg of indinavir three times a day (TID) were switched to 400 mg of indinavir BID with 400 mg of ritonavir two times a day (BID) for 48 weeks. Full pharmacokinetic evaluations were obtained for 12 subjects before the switch and 3 weeks after the switch. Combination therapy increased the indinavir predose concentrations in plasma by 6.47-fold, increased the minimum concentration in serum by 3.41-fold, and reduced the maximum concentration in serum by 57% without significantly changing the area under the plasma concentration-time curve at 24 h. At week 3, 58% (21 of 36) of the subjects for whom postbaseline measurements were available achieved a viral load in plasma of <50 copies/ml or a reduction from the baseline load of > or =0.5 log(10) copies/ml. Of these subjects, 82% (14 of 17) whose viruses had three or fewer protease inhibitor mutations and 88% (14 of 16) whose viruses had an indinavir virtual phenotypic susceptibility test of more than sixfold less than that for the baseline isolate were considered virologic responders. The indinavir virtual inhibitory quotient, which is a function of baseline indinavir phenotypic resistance (estimated by virtual phenotype) and the indinavir predose concentration in plasma achieved with indinavir-ritonavir combination therapy, was the best predictor of a viral load reduction. Sixteen subjects discontinued the study by week 48 due to adverse events, predominantly related to hyperlipidemia. Pharmacokinetic intensification of indinavir-based therapy with ritonavir reduced the viral loads in subjects but added toxicity. The virtual inhibitory quotient, which incorporates both baseline viral resistance and the level of drug exposure in plasma, was superior to either baseline resistance or drug exposure alone in predicting the virologic response.

Adult↗

PubMedDate not supplied

Simplification of antiretroviral treatment--how to sustain success, reduce toxicity and ensure adherence avoiding PI use.

Shortly after protease inhibitors (PI) began to be widely prescribed for the treatment of HIV infection in 1996, we learned that the virological efficacy of highly active antiretroviral therapy (HAART) was frequently associated with severe quality of life impairment. In fact, failure of PI-based regimens is often due to poor adherence resulting from high pill burden, complex dosing schedules, adverse events, or long-term toxicity. The metabolic and morphologic abnormalities associated with prolonged PI use are of particular concern: fat accumulation and abnormalities of lipid and glucose metabolism may increase the risk of cardiovascular disease, and body-shape changes (lipodystrophy) may also have a psychological impact or decrease patients' willingness to adhere to therapy. The efficacy of PI-sparing regimens in drug-naïve subjects, which typically consist of nucleoside reverse transcriptase inhibitors (NRTIs) with or without non-nucleoside reverse transcriptase inhibitors (NNRTIs), gives support to simplification strategies. In patients who have maintained durable virologic suppression on a PI-based regimen, the replacement of a PI by an NRTI, usually abacavir (ABC), or an NNRTI, has been shown to be associated with maintenance of virologic suppression, while leading to improvements in adherence and in some PI-related toxicities. The replacement of a PI by an NNRTI or ABC is usually followed by reductions in total cholesterol and triglycerides, though this is less true with efavirenz (EFV) than with nevirapine (NVP) or ABC. While there may be some improvement in fat accumulation after switching from a PI-based regimen, no improvement in lipoatrophy has been demonstrated after PI switches, possibly because this toxicity is due to NRTIs rather than PIs. However, NVP should be used with caution in patients co-infected patients with hepatitis B or C, and EFV may be poorly tolerated in individuals with psychiatric morbidity. Patients taking methadone may require dosage increases with switches to either NVP or EFV.

HIV Infections↗