FDA Warns Hepatitis C Drugs Could Have Deadly Side Effect

By Britni de la Cretaz 10/07/16
FDA Warns Hepatitis C Drugs Could Have Deadly Side Effect

For the many people who take direct-acting antivirals (DAA) to treat their hepatitis C, the FDA has issued a new warning.

In a statement released on Tuesday, the FDA warns that the drugs used to treat hepatitis C (HCV) have the potential to reactivate the hepatitis B virus (HBV), sometimes with deadly results. According to the statement, “In a few cases, HBV reactivation in patients treated with DAA medicines resulted in serious liver problems or death.”

As a result, the FDA says it has added a boxed warning, its “most prominent warning,” to the labels of DAA drugs.

According to the CDC, about 3.5 million Americans are currently living with HCV and roughly half are unaware of their infection. A 2016 study by the CDC found that HCV, which affects the liver, kills more Americans than any other infectious disease. In 2014, the mortality rate was at an all-time high of 19,659. These DAA medications—such as Sovaldi, Olysio, and Harvoni, among others—can often severely reduce the level of HCV in the body and, in some cases, cure the virus.

The FDA data found 24 cases with reactivation of HBV among people who were receiving treatment with DAAs for the treatment of HCV between Nov. 22, 2013, and July 18, 2016. They note, however, that the number is likely higher, because these were only the cases reported to the FDA. Of those 24 cases, two people died and one required a liver transplant. During the testing of these DAA medications, HBV co-infection was one of the exclusion criteria in order for people to be included in the trials, so no adverse effects were reported in relation to reactivation. 

According to a study published in The Lancet Infectious Diseases, many baby boomers with the virus were infected in the years following World War II, during medical procedures when transfusion blood was not yet tested for the virus. In recent years, increased numbers of the infection may be associated with the opioid epidemic and intravenous drug use. The CDC considers addressing HCV transmission among drug users to be a top priority.

At this time, it’s not clear why treating hepatitis C has the potential to reactivate the hepatitis B virus. “These medicines are not known to cause immunosuppression, but HBV reactivation may result from a complex interplay of host immunologic responses in the setting of infection with two hepatitis viruses,” according to the FDA’s statement.

"Doctors should be screening everybody" for hepatitis B before prescribing DAAs to treat HCV, Dr. John Farley, deputy director of FDA's Office of Antimicrobial Products, told NBC News. He stressed that while it was important for providers to know if a patient had co-occurring viruses, “what we don't want to do is discourage patients with hepatitis C from getting treatment."

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Britni de la Cretaz is a freelance writer, baseball enthusiast, and recovered alcoholic living in Boston. Follow her on Twitter at @britnidlc.