Boceprevir and telaprevir interact with some drugs used for HIV treatment (and vice versa). Most drug-drug interaction studies have been conducted using healthy HCV- and HIV-negative volunteers. Based on results from these studies, pharmacologists and regulatory authorities in the U.S. and Europe have made recommendations about which drugs should not be used together.
Some infectious disease experts disagree with the recommendations about drug-drug interactions because they have found that in clinical trials with HIV-positive people who were taking ART and boceprevir or telaprevir, adequate antiviral responses against both HCV and HIV were seen.
Why the differences?
There are several possible reasons why experiments with HIV-negative volunteers yielded one set of results and clinical trials with HIV-positive people a different set of results, as follows:
- Many drugs are broken down by the liver and co-infected people tend to have a greater degree of liver dysfunction than HCV-negative people and so drug levels tend to be greater among co-infected people compared to healthy volunteers. Therefore, a decrease of 30% to 50% in drug levels in some co-infected people may not have a clinically meaningful impact.
- Peginterferon is a standard part of triple HCV therapy and this may have provided additional anti-HIV activity that compensated for reduced levels of anti-HIV drugs.
As with many studies of co-infection so far, the number of participants in these studies was too small to draw meaningful conclusions. Fortunately, this situation is being addressed by the U.S. AIDS Clinical Trials Group (ACTG) and in France by the ANRS. Both organizations are recruiting co-infected volunteers to further study the complex drug-drug interactions that can occur when drugs for HIV and HCV are taken by the same person.
— Sean R. Hosein
Burger DM. Interactions between antiretrovirals and direct acting antivirals. In: Program and abstracts of the 8th International Workshop on HIV and Hepatitis Co-infection, 30 May–1 June 2012, Madrid, Spain.