Drug interactions
Captopril + Metformin
Severity: Moderate
Captopril and Metformin: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
ACE inhibitors may slightly enhance insulin sensitivity and glucose lowering, so hypoglycemia is possible but uncommon with metformin. Captopril can also worsen renal function, which could reduce metformin clearance and raise the risk of lactic acidosis.
What this interaction means in plain words
Captopril and Metformin can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Captopril belongs to Cardiovascular; Metformin belongs to Endocrine.
Why it happens
Improved insulin sensitivity from ACE inhibition, plus possible renal function decline that reduces metformin elimination.
What to do
Monitor glucose and renal function (eGFR) periodically, especially at initiation. Reduce or stop metformin if eGFR falls below labeled thresholds or during acute illness with dehydration.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Captopril
- Aliskiren + Captopril Contraindicated
- Captopril + Sacubitril / valsartan Contraindicated
- Captopril + Sacubitril-valsartan Contraindicated
- Amifostine + Captopril Major
- Amiloride + Captopril Major
- Amlodipine-hydrochlorothiazide-valsartan + Captopril Major
Other interactions of Metformin
Frequently asked questions
Can I take Captopril with Metformin?
MediHelp rates the interaction as moderate. Captopril and Metformin can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. ACE inhibitors may slightly enhance insulin sensitivity and glucose lowering, so hypoglycemia is possible but uncommon with metformin. Captopril can also worsen renal function, which could reduce metformin clearance and raise the risk of lactic acidosis.
How serious is the interaction between Captopril and Metformin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor glucose and renal function (eGFR) periodically, especially at initiation. Reduce or stop metformin if eGFR falls below labeled thresholds or during acute illness with dehydration.
What other medicines interact with Captopril?
MediHelp also lists interactions of Captopril with, for example, Aliskiren, Sacubitril / valsartan, Sacubitril-valsartan. The full list is on the Captopril page.
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