Safety and tolerance of efavirenz in different antiretroviral regimens: results from a national multicenter prospective study in 1,033 HIV-infected patients.

PURPOSE: To evaluate the incidence and severity of adverse events (AEs) and treatment interruption (TI) with efavirenz in a population with a high rate of intravenous drug use (IVDU).

METHOD: This was a national, multicenter, and observational study of HIV-infected adult patients who were starting an efavirenz-containing regimen. Evaluations of AEs were made in routine clinical practice at baseline and at least 3 months later. A total of 1,033 patients were included from 60 participating hospitals; 20% were antiretroviral naive. The risk factor for HIV infection was IVDU in 62.3%, and 6.6% of participants were on methadone.

RESULTS

AEs affected 29.3% of participants, and treatment was interrupted in 8.23%. The most frequent AEs were CNS disturbances that affected 24.1% participants; these AEs were considered related to efavirenz in 18.5% patients. AEs were not severe, and treatment had to be interrupted in 6% of patients. Other AEs were cutaneous rash (incidence of 5.9%; 2.4% of TI), gastrointestinal disturbances (1.45%; no TI), and elevation of liver function test (0.68%; no TI). Patients taking methadone had more AEs (39.7%), mainly CNS disturbances, and TI (19.1%). Cutaneous rash was more frequent among women. Psychoactive drug consumption, previous history of psychiatric disorders, antiretroviral experience, or previous nevirapine intolerance were not associated with higher incidence of AEs.

CONCLUSION

Safety and tolerance of efavirenz is good in most patients, even in a population with a high rate of IVDU. The most common AEs are CNS disturbances; they are not severe and rarely lead to TI.