Minor
Established
Deskripsi
Ranitidine competitively inhibits OCT2-mediated renal tubular secretion of metformin, modestly increasing metformin plasma concentrations.
Mekanisme
Both ranitidine and metformin are organic cations secreted by OCT2 and MATE transporters in the renal proximal tubule; competition for these transporters raises metformin AUC slightly.
Signifikansi Klinis
A pharmacokinetic study showed ranitidine increased metformin AUC by approximately 35%; this is unlikely to cause lactic acidosis in patients with normal renal function.
Penatalaksanaan
No routine dose adjustment required; caution in patients with renal impairment or other risk factors for lactic acidosis.