Interferon alpha is given by injection just under the skin and has a number of side effects, including flu-like symptoms, headaches, fever, fatigue, loss of appetite, nausea, vomiting, depression
, and thinning of hair. Treatment
with interferon alpha may also interfere with the production of white blood cells and platelets. Ribavirin is a capsule taken twice daily, and the major side effect is severe anemia (low red blood cells). Ribavirin also causes birth defects.