FDA: Do Not Mix Hepatitis B Drug Adefovir with Stribild HIV Combo Pill


The U.S. Food and Drug Administration (FDA) last week announced an update to the label information for adefovir dipivoxil (Hepsera), adding the 4-in-1 antiretroviral combination pill Stribild (elvitegravir/cobicistat/tenofovir/emtricitabine) to the list of other products that should not be co-administered with adefovir.

Adefovir is a nucleotide analog approved for treatment of chronic hepatitis B. It was once a candidate for HIV treatment (under the name Preveon), but the FDA declined approval for that indication due to concerns about kidney toxicity. The dose used to treat hepatitis B is lower, however, and the drug is generally safe and well-tolerated for that purpose, though it should not be used by people with pre-existing kidney impairment.

Adefovir for hepatitis B should not be used in combination with other drugs that could also contribute to kidney problems. The adefovir package information states that it should not be used concurrently with tenofovir (Viread) or any coformulations containing tenofovir, including Truvada (tenofovir/emtricitabine), Atripla (efavirenz/tenofovir/emtricitabine), Complera (rilpivirine/tenofovir/emtricitabine), and now the recently approved Stribild. Adefovir, tenofovir, and the tenofovir coformulations are all marketed by Gilead Sciences.

HIV/HBV coinfected people should also be aware that HIV drug resistance could emerge if adefovir or tenofovir are used alone to treat hepatitis B. Coinfected people should only use these drugs as part of a complete multi-drug antiretroviral regimen.

Full prescribing and safety information for adefovir is available online via the Drugs@FDA web site.



R Klein and K Strubel. FDA Hepatitis Update - Hepsera (adefovir dipivoxil) package insert updated to add new safety information. Media announcement. November 30, 2012.