Potentially Fatal Interaction Between Hep C Drug and Antiarrhythmic

There is a rare, but potentially fatal interaction between the antiarrhythmic agent amiodarone and the hepatitis C drug sofosbuvir (Sovaldi) or Harvoni, according to a recent letter from Gilead Sciences.

Sofosbuvir is used to treat chronic hepatitis C infection in tandem to another drug for a combination antiviral treatment, while Harvoni is indicated for chronic hepatitis C genotype 1 infection treatment in adults.
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According to experts at Gilead, 9 cases of symptomatic bradycardia were reported in patients who received amidarone with either sofobuvir or Harvoni in combination with another direct acting antiviral (DAA). Of those patients, 7 were taking a beta-blocker.

Of the 9 cases, 6 manifested within the first 24 hours following HCV treatment initiation and the other 3 cases occurred within the first 2 to 12 days following treatment.

The letter identified other adverse events from taking amidarone with either sofobuvir or Harvoni in combination with another DAA as fatal cardiac arrest and pacemaker interventions. Three of the cases called for a pacemaker intervention in patients and 1 case experienced a fatal cardiac arrest.

For treatment that requires the combination therapy of sofosbuvir and amiodorone because of limited options, Gilead recommended in-hospital monitoring for the first 48 hours of treatment followed by close cardiac monitoring by the patient’s healthcare providers.

“Due to amiodarone’s long half-life, patients discontinuing amiodarone just prior to starting Harvoni or Sovaldi in combination with a DAA should also undergo similar cardiac monitoring as outlined above,” said John McHutchison, MD, author of the letter and executive vice president of clinical research at Gilead Sciences, Inc.

The complete letter is published on Gilead’s website.

-Michelle Canales Butcher

Reference:

Gilead. Serious and life-threatening cases of symptomatic bradycardia as well as one case of fatal cardiac arrest reported with coadministration of Amiodaron with either Harvoni (ledipasivir and sofobuvir fixed-dose combination) or with Sovaldi (sofosbuvir) in combination with another direct acting antiviral. March 20, 2015. http://freepdfhosting.com/47b90580b3.pdf. Accessed March 24, 2015.