Clinical

Value of tenofovir stressed in hepatitis B and HIV co-infection

Last Updated: 2005-10-18 9:40:22 -0400 (Reuters Health)

NEW YORK (Reuters Health) - The US Food and Drug Administration has plans to add black box warnings to antiretroviral drugs that are active against both HIV and hepatitis B, alerting clinicians to the possibility of clinically significant hepatitis B relapse when these drugs are discontinued.

In the October 1st issue of Clinical Infectious Diseases, the authors of a "Viewpoints" piece "applaud the FDA for bringing this important issue to the attention of clinicians."

However, Drs. Chloe L. Thio, Mark S. Sulkowski, and David L. Thomas of Johns Hopkins University in Baltimore are concerned that in the case of tenofovir DF, the black box warning states that this drug is "not indicated for the treatment of chronic hepatitis B."

"In FDA parlance, this means that the drug has not been registered for use," they point out.

Dr. Thio and colleagues are concerned that clinicians may misinterpret the warning. "The warning does not mean that tenofovir DF is not active against HBV, nor should it be interpreted as a contraindication for use in patients with chronic hepatitis B," they write.

Tenofovir DF, a nucleotide analogue approved by the FDA for treatment of HIV infection, has "strong anti-HBV activity," the authors note, and there is "mounting clinical evidence" that the drug has an important role in the treatment of HBV infection in HIV-infected populations. Current US guidelines support the use of tenofovir DF in this patient population, they add.

"In our opinion," Dr. Thio and colleagues write, "tenofovir DF should be strongly considered as treatment for chronic hepatitis B when an adult patient also needs HIV treatment."

"Clearly, the strength of our recommendation for the use of tenofovir DF would be much greater if the drug had been licensed for treatment of chronic hepatitis B, but the use of tenofovir DF is easily justified in light of available data," they write.

Summing up, Drs. Thio, Sulkowski, and Thomas say the black box warnings on tenofovir and other antivirals with anti-HBV activity "appropriately" highlight the possibility of severe acute exacerbations of HBV after discontinuation in HBV-HIV co-infected patients.

However, they contend that, at present, "the best approach" to the treatment chronic hepatitis B in HIV-infected patients will require thinking "outside the black box."

Clin Infect Dis 2005;41:1035-1040.