FRIDAY, Oct. 23, 2015 (HealthDay News) -- Reports of deaths and illnesses occurring soon after use are prompting the U.S. Food and Drug Administration to issue warnings on two drugs used to fight the hepatitis C virus.
The drugs, called Viekira Pak and Technivie, appeared linked to serious liver damage in patients with advanced liver disease, the agency warned in a statement issued Thursday.
Of 26 cases reported worldwide where use of the medications has been the possible or probable cause of illness, 10 patients either died or required organ transplant after liver failure, and 16 patients had some form of liver dysfunction. In most cases, liver damage occurred within one to four weeks of patients starting treatment, the FDA said.
The cases occurred after the two drugs were approved by the FDA -- Viekira Pak in December of 2014 and Technivie in July of 2015, the statement said. The agency believes that there may be other cases that have gone unreported.
Based on the reports, the FDA is now warning that "Viekira Pak and Technivie may cause serious liver injury, including life-threatening liver failure, mainly in patients with underlying advanced liver disease."
And, "as a result," the agency added, "we are requiring the manufacturer [AbbVie] to add new information about this safety risk to the drug labels."
The FDA says that anyone taking Viekira Pak or Technivie who begins experiencing "fatigue, weakness, loss of appetite, nausea and vomiting, yellow eyes or skin, or light-colored stools" should contact their doctor immediately, as these symptoms might indicate liver injury.
"Patients should not stop taking these medicines without first talking to their health care professionals," the FDA added, because "stopping treatment early could result in drug resistance to other hepatitis C medicines."
Viekira Pak and Technivie are used to treat patients with chronic hepatitis C, an infection that can last a lifetime and lead to serious liver and other health problems, including cirrhosis, liver cancer and death. These drugs lower the amount of hepatitis C virus in the body by preventing it from multiplying and may slow down the disease, the FDA statement explained.
Viekira Pak is a combination of dasabuvir, ombitasvir, paritaprevir, and ritonavir used with or without ribavirin, another hepatitis C medicine. It is approved for use in patients with genotype 1 chronic hepatitis C infection, including those with the liver ailment known as compensated cirrhosis.
Technivie is a combination of ombitasvir, paritaprevir and ritonavir, used in combination with ribavirin. It is approved for use in patients with genotype 4 chronic hepatitis C virus infection without cirrhosis.
According to the FDA, before taking Viekira Pak or Technivie, patients should tell their doctors if they: have liver problems other than hepatitis C infection or have HIV infection or are taking birth control pills that contain ethinyl estradiol.
Common side effects of Viekira Pak or Technivie include nausea, itching, and sleep problems.
Between its approval in December 2014 through August 2015, it's estimated that Viekira Pak has been prescribed to more than 10,000 patients in the United States, but there is no data on how many prescriptions have been written for Technivie since its approval in July 2015, the FDA said.
The American Academy of Family Physicians has more about hepatitis C.