The drugs, which are exceedingly successful against hepatitis C, may trigger inactive hepatitis B in patients contaminated with both sorts, the European Medicines Agency said in an announcement.
It named the antivirals Daklinza, Exviera, Harvoni, Olysio, Sovaldi and Viekirax used to treat endless hepatitis C, an irresistible liver ailment.
"Instances of the arrival of beforehand dormant hepatitis B disease, which can be lethal, have been accounted for in patients treated," with this class of medication, the organization said in an announcement reporting the discoveries of a test.
There have been just around 30 instances of hepatitis B reactivation out of a large number of patients taking the medications, the office said. What's more, there was insufficient data to reach a determination on malignancy chance.
In any case, an exceptional hazard evaluation council of the organization prescribed that all patients be screened for hepatitis B infection before beginning any of these medicines.
It likewise suggested that a notice be incorporated into the medication data handout.
The medications, another class known as "immediate acting antivirals" are more successful than their ancestors.
At a cost of approximately 40,000 to 80,000 euros ($43,000-$86,000) for a 12-week course, they are the safeguard of a fortunate few.
Hepatitis is an irritation of the liver, regularly brought about by an infection yet at times by medication or liquor mishandle, different contaminations, or immune system illnesses.
The B and C sorts for the most part happen from contact with body liquids of a contaminated individual. Other than for hepatitis B, there is no antibody against hepatitis C.