If a serious skin reaction occurs, all components of INCIVEK combination treatment must be discontinued immediately and the patient should be promptly referred for urgent medical care.

5.3 Rash
Rash developed in 56% of subjects who received INCIVEK combination treatment [see Adverse Reactions (6.1)]. Severe rash (e.g., a generalized rash or rash with vesicles or bullae or ulcerations other than SJS) was reported in 4% of subjects who received INCIVEK combination treatment compared to less than 1% who received peginterferon alfa and ribavirin alone. The severe rash may have a prominent eczematous component.

Patients with mild to moderate rashes should be followed for progression of rash or development of systemic symptoms. If rash progresses and becomes severe or if systemic symptoms develop, INCIVEK should be discontinued. Peginterferon alfa and ribavirin may be continued. If improvement is not observed within 7 days of INCIVEK discontinuation, sequential or simultaneous interruption or discontinuation of ribavirin and/or peginterferon alfa should be considered. If medically indicated, earlier interruption or discontinuation of ribavirin and peginterferon alfa should be considered. Patients should be monitored until the rash has resolved. INCIVEK must not be reduced or restarted if discontinued due to rash. Treatment of rash with oral antihistamines and/or topical corticosteroids may provide symptomatic relief but effectiveness of these measures has not been established. Treatment of rash with systemic corticosteroids is not recommended [see Drug Interactions (7)].

5.4Anemia
Anemia has been reported with peginterferon alfa and ribavirin therapy. The addition of INCIVEK to peginterferon alfa and ribavirin is associated with an additional decrease in hemoglobin concentrations. Hemoglobin values less than or equal to 10 g/dL were observed in 36% of subjects who received INCIVEK combination treatment compared to 17% of subjects who received peginterferon alfa and ribavirin. Hemoglobin values less than 8.5 g/dL were observed in 14% of subjects who received INCIVEK combination treatment compared to 5% of subjects receiving peginterferon alfa and ribavirin.

In subjects receiving INCIVEK combination treatment, 4% discontinued INCIVEK, 1% discontinued INCIVEK combination treatment, and 32% underwent a ribavirin dose modification (reduction, interruption or discontinuation) due to anemia. In subjects treated with peginterferon alfa and ribavirin alone, there were two discontinuations and 12% underwent ribavirin dose modification due to anemia.

Hemoglobin should be monitored prior to and at least every 4 weeks during INCIVEK combination treatment. For the management of anemia, ribavirin dose reductions should be used (refer to the prescribing information for ribavirin for its dose reduction guidelines). If ribavirin dose reductions are inadequate, discontinuation of INCIVEK should be considered. If ribavirin is permanently discontinued for the management of anemia, INCIVEK must also be permanently discontinued. Ribavirin may be restarted per the dosing modification guidelines for ribavirin. The dose of INCIVEK must not be reduced and INCIVEK must not be restarted if discontinued.

5.5Drug Interactions
See Table 3 for a listing of drugs that are contraindicated for use with INCIVEK