الوصف
Furosemide can increase metformin plasma concentrations and potentially contribute to lactic acidosis by reducing renal function; furosemide also impairs glucose metabolism and may worsen glycaemic control.
الآلية
Furosemide reduces renal tubular secretion of metformin through competition for organic cation transporter (OCT2/MATE1) pathways, increasing metformin AUC by ~22%. Additionally, furosemide-induced volume depletion reduces GFR, raising lactic acidosis risk with metformin.
الأهمية السريرية
Pharmacokinetic studies confirm modest increases in metformin exposure; the clinical concern is primarily around renal function deterioration precipitating metformin accumulation and lactic acidosis.
التدبير
Monitor renal function and serum lactate in patients on both agents; hold metformin if eGFR drops below 30 mL/min/1.73 m²; monitor blood glucose as furosemide may worsen hyperglycaemia.