Moderate
Hydrochlorothiazide × Metformin
Thiazide diuretics×Biguanides. Oral antihyperglycemic agents
Mechanism
Thiazide diuretics reduce glycaemic control via hypokalaemia-driven suppression of insulin secretion. HbA1c may rise by 0.3–0.5%, especially in the first 6 months.
Symptoms
Return of thirst and polyuria, rising fasting glucose, signs of worsening control. Symptoms are typically mild.
Management
Check fasting glucose and HbA1c 3 months after starting hydrochlorothiazide. If HbA1c rises, increase metformin or add another glucose-lowering agent. Potassium every 6 months. In overt diabetes decompensation, alternatives: indapamide (less metabolic effect) or an SGLT-2 inhibitor.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.
Sources
- Lexicomp: Lexicomp Drug Interactions (2024)– Wolters Kluwer Clinical Drug Information, Inc. Lexi-Interact Online, 2024
- ESC: 2024 ESC Guidelines for the management of elevated blood pressure and hypertension (2024)– Eur Heart J 2024;45(38):3912–4018
- AGS: American Geriatrics Society Beers Criteria for Potentially Inappropriate Medication Use (2023)– By the 2023 American Geriatrics Society Beers Criteria Update Expert Panel. AGS Beers Criteria for Potentially Inappropriate Medication Use in Older Adults. J Am Geriatr Soc 2023;71(7):2052-2081.