التداخل بين سيميتيدين ودوفيتيليد

The concomitant use of verapamil or the cation transport system inhibitors cimetidine, trimethoprim (alone or in combination with sulfamethoxazole), or ketoconazole with dofetilide is contraindicated (see WARNINGS and PRECAUTIONS, Drug-Drug Interactions ), as each of these drugs cause a substantial increase in dofetilide plasma concentrations.

The magnitude of the effect on renal elimination by cimetidine, trimethoprim, and ketoconazole (all contraindicated concomitant uses with dofetilide) suggests that all renal cation transport inhibitors should be contraindicated.

Drug-Drug Interactions Cimetidine: (see WARNINGS, CONTRAINDICATIONS ) Concomitant use of cimetidine is contraindicated.

Cimetidine at 400 mg BID (the usual prescription dose) co-administered with dofetilide (500 mcg BID) for 7 days has been shown to increase dofetilide plasma levels by 58%.

Cimetidine at doses of 100 mg BID (OTC dose) resulted in a 13% increase in dofetilide plasma levels (500 mcg single dose).