Coadministration of ethinyl oestradiol/levonorgestrel (0.03/0.15 mg single dose) and elbasvir (50 mg once daily) increased ethinyl oestradiol AUC and Cmax by 1% and 10%; levonorgestrel AUC and Cmax increased by 14% and 2%. Coadministration of ethinyl oestradiol/levonorgestrel (0.03/0.15 mg single dose) and grazoprevir (200 mg once daily) increased ethinyl oestradiol AUC and Cmax by 10% and 5%; levonorgestrel AUC increased by 23% but Cmax decreased by 7%. No dose adjustment is required.

The interaction between elbasvir or grazoprevir and oral contraceptive pills was evaluated in clinical studies and no dose adjustments are needed. Administration of ethinylestradiol/levonorgestrel (0.03/0.15 mg single dose) to 20 subjects increased ethinyl estradiol AUC and Cmax by 1% and 10% when coadministered with elbasvir (20 mg once daily) and by 10% and 5% when coadministered with grazoprevir (200 mg once daily). Levonorgestrel AUC and Cmax increased by 14% and 2% when coadministered with elbasvir while AUC increased by 23% and Cmax decreased by 7% when coadministered with grazoprevir. Elbasvir AUC and Cmax increased by 14% and 2%, respectively, while grazoprevir AUC increased by 23% and Cmax decreased by 7%.