Ranolazine and metformin may be frequently co-administered in subjects with chronic angina and co-morbid type 2 diabetes mellitus (T2DM). The potential for a drug-drug interaction was explored in two phase 1 clinical studies in subjects with T2DM to evaluate the pharmacokinetics and safety of metformin 1000 mg BID when administered with ranolazine 1000 mg BID (Study 1, N = 28) or ranolazine 500 mg BID (Study 2, N = 25) as compared to metformin alone. Co-administration of ranolazine 1000 mg BID with metformin 1000 mg BID resulted in 1.53- and 1.79-fold increases in steady-state metformin Cmax and AUCtau , respectively; co-administration of ranolazine 500 mg BID with metformin 1000 mg BID resulted in 1.22- and 1.37-fold increases in steady-state metformin Cmax and AUCtau , respectively. Co-administration of ranolazine and metformin was well tolerated in these T2DM subjects, with no serious adverse events or drug-related adverse events leading to discontinuation. The most common adverse events were nausea, diarrhea, and dizziness. These findings are consistent with a dose-related interaction between ranolazine and metformin, and suggest that a dose adjustment of metformin may not be required with ranolazine 500 mg BID; whereas, the metformin dose should not exceed 1700 mg of total daily dose when using ranolazine 1000 mg BID.
Keywords: chronic angina; drug interactions; metformin; pharmacokinetics; ranolazine; type 2 diabetes mellitus.
© 2015, The American College of Clinical Pharmacology.