Making Sense of the Drug Interaction Warning for HIV/HCV-Coinfected Patients Taking Victrelis

In April of 2010, an advisory panel to the U.S. Food and Drug Administration (of which I am a member) urged approval of the hepatitis C (HCV) protease inhibitor Victrelis (boceprevir) for the treatment of patients with HCV infection. At the same time, we also requested more studies on drug interactions between Victrelis and HIV drugs in preparation for treatment studies in the HIV/HCV-coinfected patient.

Sometimes drug interactions are a good thing because they can lead to increased levels of a medication, which may help it work better. For example, the HIV protease inhibitors Kaletra (lopinavir), Prezista (darunavir) and Reyataz (atazanavir) are usually given with Norvir (ritonavir) to boost their levels in your blood. This leads to great suppression of your HIV infection.

But drug interactions can also be a bad thing because sometimes they cause low drug levels in your blood. Low drug levels can lead to loss of control of your HIV. Unfortunately, a study of drug interactions between Victrelis and Norvir-boosted HIV protease inhibitors in healthy volunteers has now shown that blood levels of these HIV drugs went down too low. In addition, Victrelis blood levels went down too low as well. This is really disappointing news.

What does this mean? Low blood levels usually mean that the effectiveness of your HIV and your HCV treatment is not as good as it should be.

What should you do? If you are taking Victrelis with HIV medications, contact your doctor to see if you need to change your HIV medications. Right now, the safest bet is to take Truvada (tenofovir/FTC) plus Isentress (raltegrevir) because there aren't any interactions with Victrelis to worry about. However, all changes to your HIV medications need to be discussed carefully with your HIV doctor who knows you best.

For any of you who are taking the other recently approved HCV protease inhibitor, Incivek (telaprevir), along with HIV medications, the drug interactions have been studied already and we already know which HIV medications you should take. As with Victrelis, some drug interactions can lead to low blood levels. That is why Incivek is only recommended with one of the following HIV treatment regimens:

  1. Truvada plus Norvir-boosted Reyataz
  2. Truvada plus Sustiva (also known as Atripla; if you go with this option, your doctor will give you extra Incivek to boost drug levels)
  3. Truvada plus Isentress

As you can see, you have more HIV drug choices if you take Incivek. This may help you and your doctor figure out which HCV treatment is best for you.