A pilot study of combination therapy with initial high-dose interferon and amantadine hydrochloride for patients with chronic hepatitis C with the genotype 1b virus.

BACKGROUND/AIMS: Interferon monotherapy for patients with chronic hepatitis C has been suboptimal. We studied the effect of the combination therapy of an initial high-dose of interferon and amantadine. METHODOLOGY: We investigated the virological response of 20 patients with naive chronic hepatitis C with a high viral load of the genotype 1b virus. Seven patients were administered 6MU of interferon-beta once daily for 6 weeks and then thrice weekly for 20 weeks, and 13 were administered 6 MU of interferon-beta daily for 4 or 6 weeks and then 10 MU of natural interferon-alpha thrice weekly for 22 or 20 weeks. All patients were treated with amantadine hydrochloride (100 mg/day) for 26 weeks during interferon administration. RESULTS: The complete response, transient response and no response rate were 15.0%, 60.0%, and 25%, respectively. After daily administration of interferon-beta intravenously, 19 patients (95.0%) showed negative tests for serum HCV-RNA by the polymerase chain reaction method. At the end of treatment, the serum HCV-RNA was not detected in any patients treated with daily interferon-beta and intermittent interferon-alpha with amantadine. At 6-month follow-up, three patients had eradicated HCV-RNA, who were in the group of daily interferon-beta and intermittent interferon-alpha with amantadine. In the patients treated with daily interferon-beta and intermittent interferon-alpha with amantadine, the complete response, transient response and no response rates were 23.1%,-76.9% and 0%, respectively. CONCLUSIONS: These findings suggest that the combination of an initial high-dose interferon and amantadine shows promising effects on the eradication of HCV-RNA in the chronic hepatitis C patients with a high viral load of the genotype 1b virus.

The combination therapy of interferon and amantadine hydrochloride for patients with chronic hepatitis C.

BACKGROUND/AIMS: The effect of interferon treatment for chronic hepatitis C patients with genotype 1b virus has been suboptimal. We studied the effect of the combination therapy of interferon and amantadine on patients with a high serum viral load of genotype 1b virus. METHODOLOGY: We studied the virological response of naive chronic hepatitis C patients with a high viral load of genotype 1b virus (4.5 log copies/50 microL or 100 kcopies/mL and higher) during interferon and amantadine administration for 6 months and 6 months after the end of treatment. Twenty patients were treated with interferon alone (natural interferon-beta 6 MU daily for 6 weeks and thrice-a-week for 20 weeks) for 26 weeks. Eleven patients were treated with the combination therapy of interferon and amantadine hydrochloride (100 mg orally daily) for 26 weeks. RESULTS: After daily administration of interferon-beta intravenously once a day for 6 weeks, all patients showed the negative tests of serum HCV-RNA by polymerase-chain-reaction methods by the combination therapy, while 13 patients (65.0%) showed the negative tests by interferon alone (p = 0.0257). At the end of treatment, serum HCV-RNA were not detected in 54.5% of patients treated with interferon and amantadine, while it was detected in 50.0% of patients treated with interferon alone. At 6 months follow-up, only one patient (9.1%) could eradicate HCV-RNA in patients with interferon and amantadine, while no patient could with interferon monotherapy (not significantly). CONCLUSIONS: Amantadine hydrochloride has the additive effects to interferon treatment on the virological responses of serum HCV-RNA during a co-administration, although the combination therapy has not shown a significantly promising effect on the eradication of HCV-RNA in the patients with chronic hepatitis C with a high viral load of genotype 1b virus.