Entacavir (Baraclude) Gets Boxed Warning About HIV Resistance

ROCKVILLE, Md., Aug. 17 -- The FDA has added a boxed warning to the litany of cautions about the use of entacavir (Baraclude), a hepatitis B drug, for certain patients co-infected with HIV.

The boxed warning inserted in the label of entacavir cites the potential for promoting HIV resistance when it is used to treat HIV-hepatitis B co-infected patients not also receiving highly active antiretroviral therapy (HAART).

The label change follows a preliminary report in February about HIV resistance in such dual infected patients. It prompted a letter to physicians by the drug-maker, Bristol-Myers Squibb, warning of the possibility of generating HIV resistance. (See CROI: HIV Resistance Linked to Hepatitis Drug)

The boxed warning notes limited clinical experience suggesting the potential for development of resistance to HIV nuceloside reverse transcriptase inhibitors in hepatitis B patients untreated for HIV.

In a letter to physicians, Bristol-Myers Squibb said that HIV testing should be conducted in all hepatitis B virus patients prior to starting treatment with entracavir.

In April, the Department of Health and Human Services changed its treatment guidelines for hepatitis B to recommend against the use of the drug "without concomitant treatment for HIV."

In June, there was a report in the New England Journal of Medicine that use of entracavir in dual infected patients who were not receiving HAART led to the accumulation of HIV variants with the M184V mutation, which confers resistance to the nucleoside reverse transcriptase inhibitors lamivudine (3TC) and emtricitabine (Emtriva). (See Hepatitis Drug May Generate HIV Resistance)