Drug interactions
Metformin + Triamterene
Severity: Moderate
Metformin and Triamterene: 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
Both drugs are cationic and handled by renal tubular transporters such as OCT2 and MATE, so triamterene may raise metformin exposure. This could increase the risk of lactic acidosis in patients with reduced renal function.
What this interaction means in plain words
Metformin and Triamterene 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.
Metformin belongs to Endocrine; Triamterene belongs to Cardiovascular.
Why it happens
Triamterene inhibits renal organic cation transporters (OCT2/MATE), reducing metformin tubular secretion.
What to do
Monitor glycemic control and renal function, and reduce the metformin dose if renal function declines or adverse effects appear.
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 Triamterene
- Amiloride + Triamterene Contraindicated
- Eplerenone + Triamterene Contraindicated
- Potassium citrate / citric acid + Triamterene Contraindicated
- Potassium citrate + Triamterene Contraindicated
- Spironolactone + Triamterene Contraindicated
- Aceclofenac + Triamterene Major
Other interactions of Metformin
Frequently asked questions
Can I take Metformin with Triamterene?
MediHelp rates the interaction as moderate. Metformin and Triamterene 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. Both drugs are cationic and handled by renal tubular transporters such as OCT2 and MATE, so triamterene may raise metformin exposure. This could increase the risk of lactic acidosis in patients with reduced renal function.
How serious is the interaction between Metformin and Triamterene?
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 glycemic control and renal function, and reduce the metformin dose if renal function declines or adverse effects appear.
What other medicines interact with Triamterene?
MediHelp also lists interactions of Triamterene with, for example, Amiloride, Eplerenone, Potassium citrate / citric acid. The full list is on the Triamterene page.
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