Reuters Health Information (2004-01-13): Amantadine of no benefit in hepatitis C infection
Amantadine of no benefit in hepatitis C infection
Last Updated: 2004-01-13 17:25:57 -0400 (Reuters Health)
NEW YORK (Reuters Health) - The addition of amantadine to a regimen of interferon alfa-2b and ribavirin does not improve outcomes in patients with chronic hepatitis C viral (HCV) infection, researchers in the U.S. report.
Amantadine is an antiviral drug with activity against the flaviviridae family, but clinical trials of the agent used to treat HCV have yielded conflicting results. A sustained response is achieved in fewer than half of patients with HCV treated with interferon plus ribavirin, the authors note in their paper.
In fact, lead author Dr. P. J. Thuluvath and colleagues write in the January issue of Gut, "We believe that amantadine should be abandoned as a potential agent for the treatment of HCV."
In their prospective study, Dr. Thuluvath, at Johns Hopkins University in Baltimore, and his team treated 171 patients with interferon alfa-2b 3 million units s.c. three times a week and ribavirin 1000 to 1200 mg daily for 24 weeks, with treatment continuing for 48 weeks if HCV RNA clearance was noted by PCR after 24 weeks. Eighty-five were randomly assigned to co-treatment with amantadine hydrochloride 100 mg b.i.d. and 86 were assigned to placebo.
Adverse event profiles were similar in the two groups, and withdrawal rates did not differ significantly. After 48 weeks of treatment, HCV RNA clearance rates were 40.6% among 28 patients remaining in the amantadine group and 47.8% of 33 in the placebo group. At 72 weeks, only 21 patients in the amantadine group and 24 in the placebo group were available for evaluation; response rates were 30.4% and 34.8%, respectively.
"We assumed that our study had the power to show a moderate difference if it existed," the investigators write, "but we did not find even a trend favoring triple therapy."