What is known is that if ribavirin is used by itself, it is not effective in decreasing the number of hepatitis C virus in the blood, although it may normalize the liver enzymes and even improve the amount of inflammation on liver biopsy. So by itself, it appears to have an anti-inflammatory action. When combined with interferon, however, it greatly enhances the ability of the interferon to kill the hepatitis C virus. For patients with hepatitis C who have never been treated with interferon, the combination of ribavirin and interferon is more effective than interferon alone. Response is more likely in those patients in whom the amount of virus decreased significantly during treatment with interferon, but never disappeared completely.
Ribavirin is taken twice a day by mouth.
Depending on body weight, patients take 5 or 6 capsules a day. Like any other medicine, side effects may occur, and at times may be serious. Adding ribavirin to interferon does not change much the well known side-effects of interferon, with the exception of a slight increase in the frequency of fatigue, insomnia, irritability and nausea. The main side effect that can be serious is anemia, or low blood count. The blood count drops in almost everyone who takes the medicine, but rarely enough to cause any symptoms or problems.