Drug interactions are important because they can lead to drug levels that are either too high or too low. In light of these concerns, more drug companies are looking at potential hepatitis C (HCV) drug interactions with HIV medications.

Remember the drug interactions that were reported between the HCV protease inhibitor Victrelis (boceprevir) and HIV drugs? In a previous blog entry, I mentioned that there were some really important drug interactions that led to lower blood levels of Victrelis and lower blood levels of some HIV drugs, such as Reyataz (atazanavir). The same is true for Incivek (telaprevir). There are a lot of drugs that should not be combined with Incivek, such as Kaletra (lopinavir/ritonavir) and Prezista (darunavir, TMC114).

The latest HCV drug in development to be tested for interactions is daclatasvir. I know, the name doesn't exactly roll off your tongue, but it is a promising new drug for HCV treatment. It is a NS5A replication complex inhibitor, which bascially means that it works on a different part of the HCV virus life cycle than protease inhibitors and other HCV medications.

Daclatasvir was studied along with asunaprevir (an HCV protease inhibitor in development) in a small study of HCV-monoinfected patients who previously didn't respond to PEG interferon plus ribavirin. In results presented at CROI 2012, the use of "quad" (four-drug) therapy consisting of daclatasvir plus asunaprevir plus PEG intereferon plus ribavirin led to cures for nine out of 10 patients. In addition, four out of 11 patients who only got the two new HCV drugs (i.e., not PEG interferon or ribavirin) were cured of their HCV infection. Although this is a small study to "test out the waters," these are pretty amazing results. Much larger trials are now planned in HCV-monoinfected patients.

To get ready for future trials in HIV/HCV-coinfected patients, the makers of daclatasvir did three separate studies in healthy volunteers. One study looked at drug interactions between the NRTI Viread (tenofovir) and daclatasvir; another at drug interactions between the NNRTI Sustiva (efavirenz, Stocrin) and daclatasvir; and the last one looked at interactions between daclatasvir and the protease inhibitor Reyataz boosted with Norvir (ritonavir).

The good news here is that daclatasvir doesn't seem to affect levels of Sustiva, boosted Reyataz or Viread. That means that these HIV meds should still work just as well as before.

However, it looks as if the dose of daclatasvir may have to be lower in people taking Reyataz. On the other hand, the dose of daclatasvir may have to be higher in people taking Sustiva.

The next step is to try these new doses of daclatasvir in HIV/HCV-coinfected patients to see if they work well in curing HCV. Let's keep our fingers crossed.

If you have questions about treating HIV/hepatitis C coinfection, Dr. McGovern is available to answer them! Visit our "Ask the Experts" forum on Hepatitis & HIV Coinfection to ask Dr. McGovern your question or browse her archive of answers.

Get email notifications every time this blog is updated.

Talk to a Physician About HIV/Hepatitis Coinfection in Our "Ask the Experts" Forums More on Hepatitis C Drugs in Development

BLOG:
Making Progress on HCV Treatment in HIV-Infected Patients

Barbara McGovern, M.D., is an associate professor of medicine at the Tufts University School of Medicine and an attending physician in the Division of Infectious Diseases at Lemuel Shattuck Hospital in Boston. She is a widely published researcher and frequent lecturer on issues pertaining to HIV and coinfections with hepatitis B and hepatitis C. More information about Dr. McGovern is available on her bio page.

Recent Posts:

View All Posts

A Brief Disclaimer:

The opinions expressed by TheBody.com's bloggers are entirely their own, and do not necessarily reflect the views of TheBody.com itself.

TheBody.com App for iPhones My Health Tracker Medication and Health Reminders Assess Your Risk for HIV Follow Us: Facebook, Twitter, RSS U.S. ASO Finder

The Body: About The Body | Contact The Body | Content Policy | Content Providers | Advertise With Us | Site Map

Remedy Health Media: About Remedy Health Media | Contact Remedy Health Media | Terms of Use | Privacy Policy

The Body is a service of Remedy Health Media, LLC, 250 West 57th Street, New York, NY 10107. The Body and its logos are trademarks of Remedy Health Media, LLC, and its subsidiaries, which owns the copyright of The Body's homepage, topic pages, page designs and HTML code. General Disclaimer: The Body is designed for educational purposes only and is not engaged in rendering medical advice or professional services. The information provided through The Body should not be used for diagnosing or treating a health problem or a disease. It is not a substitute for professional care. If you have or suspect you may have a health problem, consult your health care provider.