Dosing IFN in the evening and pre-medicating with ibuprofen is often used to reduce myalgias. Paradoxical worsening of hepatitis may also occur, and is thought to be due to an autoimmune response. Treatment should be discontinued in patients who have rising serum ALT levels to greater than twice the baseline. Ribavirin can produce hemolytic anemia, which can be life threatening in patients who have heart disease and cerebral vascular disease. Close monitoring of the patient and blood counts are imperative.
Ribavirin can also cause fatigue, pruritus, rash, and nasal stuffiness.
Furthermore, ribavirin is teratogenic, and therefore contraindicated in women patients who are considering becoming pregnant and their male partners. Sexually active women and men should use birth control during treatment and for at least six months after completion of a ribavirin regime. A male prisoner leaving prison fewer than six months after cessation of treatment needs to be warned to avoid having unprotected sex, leading to pregnancy with a female partner, until risk of teratogenicity has passed. The incidence and severity of side effects can be very high. Without a good support system, a high percentage of patients will fail to complete therapy.