varenicline and Tagamet Interactions

Interactions between varenicline and Tagamet (cimetidine)

cimetidine and varenicline (Minor Drug-Drug)

Coadministration with cimetidine has been shown to slightly increase the plasma concentrations of varenicline. The proposed mechanism is cimetidine inhibition of the active renal secretion of varenicline via human organic cation transporter, OCT2. When cimetidine (300 mg orally four times a day) was given with varenicline (2 mg single oral dose) to 12 smokers, the systemic exposure (AUC) of varenicline increased by 29%. This increase is not expected to be clinically relevant, and a dosage adjustment should not be necessary.