Higher Non Nucleoside and Lower Lopinavir Levels in HIV-HCV Coinfected Patients

By Brian Boyle, MD

In a study presented at the 3^rd IAS Conference in Rio de Janeiro, French investigators compared trough plasma antiretroviral (ARV) concentrations (Cmin) in HIV/HCV pts with a documented liver biopsy within two years and HIV patients who were not HCV-infected, matched according to sex and ARVs.

The study enrolled 73 HIV/HCV co-infected and 66 HIV mono-infected patient with, respectively, 68% and 83 % having an HIV RNA level <200 copies/mL and a median CD4 cell count of 331 and 385 cells/mm3.

The median protease inhibitor (PI) Cmin levels were similar in the two groups, except for lopinavir (LPV) which was lower in HIV/HCV patients. (Table)

Both efavirenz/EFV (Sustiva) and nevirapine/NVP (Viramune) Cmin levels were higher in HIV-HCV patients (Table) and those with more advanced fibrosis/cirrhosis had higher Cmin levels than those with lower grades of fibrosis or those who were not infected with HCV.

The authors conclude from these data that “HIV-HCV patients Cmin did not change significantly for PI except for lopinavir, but NNRTI were strongly overdosed in HIV-HCV pts suggesting the need of drug monitoring in this population.”

These data confirm prior data regarding the NNRTIs, but the lopinavir results are surprising since it is hepatically metabolized and one would expect an increase in levels, not the decrease that was found, with declining hepatic function.

The author’s call for therapeutic drug monitoring of NNRTI levels in HIV-HCV co-infected patients appears warranted in patient’s experiencing significant NNRTI-related side effects or toxicity, but the need for that testing in every HIV-HCV patient remains unsettled.

08/10/05

Reference
S Dominguez and others. The HEPADOSE study: evaluation of protease inhibitors and non nucleoside analogue plasma concentrations in HIV/HCV and HIV infected patients. Abstract WePp0305. 3^rd International AIDS Society Conference on HIV Pathogenesis and Treatment. July 24-27, 2005. Rio de Janeiro, Brazil.