Nevirapine no more likely to cause liver toxicity than other antiretrovirals

Nevirapine is no more likely than any other antiretroviral to cause liver side-effects, according to a study presented to the Fourteenth International AIDS Conference in July.

The Viramune Hepatic Safety Project was conducted by nevirapine’s manufacturer Boehringer Ingelheim. Its primary objective was to identify risk factors for antiretroviral-related liver toxicities.

Data from over 1,700 nevirapine-treated patients and 1,900 control patients who took part in Boehringer-sponsored clinical trials was analysed together with information from 814 people treated with nevirapine in non-Boehringer trials. In addition, over the records of over 5,000 patients enrolled in observational cohorts were analysed for risk factors of hepatic side-effects.

Investigators found that asymptomatic hepatic side-effects, indicated by increases in ALT/AST levels occurred in between 0.5% and 9% of people participating on Boehringer trials, and were comparable to the levels observed in the control populations (up to 7.5%). A CD4 count above 400cells/mm³ in men and 250 cells/mm³ in women was identified as a weak risk factor.

Symptomatic liver toxicities were rare in people treated with nevirapine (between 1% and 5% of people participating in Boehringer trials) and were not significantly higher than those observed in controls. Investigators also noted that hepatic toxicities ceased with the discontinuation of nevirapine treatment and were associated with a rash in 46% of people. There were insufficient data to determine if elevated ALT/AST levels at baseline or coinfection with hepatitis B or C increased the chances of liver toxicities or rash.