<p>May potentiate P-gp substrates (eg. Digoxin), CYP2C19 substrates (eg. Dose limit of Omeprazole is upto 40mg daily). May antagonize CYP3A substrates. Antagonizes oral Midazolam, Rosuvastatin; consider increasing their doses. Maybe antagonized by CYP3A inducers. Reduces efcacy with estrogen-containing contraceptives.</p>