Mealey's (November 2, 2016, 12:09 PM EDT) -- SILVER SPRING, Md. — The Food and Drug Administration on Oct. 4 warned that patients treated with direct-acting antiviral (DAA) drugs to treat hepatitis C are at risk of having an underlying hepatitis B (HBV) infection reactivated.

The FDA said that in a few cases, HBV reactivation resulted in serious liver problems or death.  It said hepatitis C drugs could reactivate HBV within four to eight weeks.

As a result, the FDA said it is requiring black box warnings on hepatitis C DAAs about the risk...