Objectives: To evaluate the frequency of and predictive factors for nevirapine-based highly active antiretroviral therapy (HAART) discontinuation.
Methods: All patients receiving nevirapine as a component of HAART at our centre were retrospectively evaluated for efficacy and tolerability. Logistic regression was used to evaluate the influence of baseline characteristics on the outcome and Kaplan-Meier (KM) estimates to evaluate time-dependent variables.
Results: Between January 1999 and June 2006, 582 patients (72% males) received 744 nevirapine-based HAART regimens. Naive patients counted for 83 of these regimens; of the remaining 661 regimens administered to experienced patients, 306 were failing virologically and 355 were undergoing simplification strategies. A once-a-day schedule was used in 136 patients. The likelihood of maintaining the nevirapine-based regimen was statistically (P < 0.0001 in both cases) influenced by the patient's status (mean KM estimate of 812 days for virological failures, 1294 for naive patients and 1657 for treatment simplifications) and by the dosing schedule (once-daily 1315 days; twice-daily 1198 days). The most frequent reason for treatment discontinuation was resistance (17.5%) followed by reduced tolerability (16.3%), patient's decision (14%) and treatment strategies such as structured treatment interruptions (13.8%). During 10.2% of treatments, a grade 3 or greater increase in aminotransferase levels was observed, reflecting an overall incidence rate equal to 5.3 cases per 100 person-years. This lead to treatment discontinuation in 3.9% of cases.
Conclusions: Nevirapine, especially when used in simplification strategies, enables doctors to extend the use of HAART over a long period of time. The risk of drug-induced hepatotoxicity is low, but nevirapine should be used with caution in patients co-infected with hepatitis C virus or with elevated liver function tests. As with any decision to prescribe a drug, a careful evaluation of the potential risks and benefits of using nevirapine must be made for each individual.