Drug interactions
Metformin + Procainamide
Severity: Moderate
Metformin and Procainamide: 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 are eliminated by renal tubular secretion, so metformin may raise procainamide and its metabolite NAPA levels. This could increase the risk of arrhythmia or other procainamide toxicity, particularly in renal impairment.
What this interaction means in plain words
Metformin and Procainamide 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.
Why it happens
Competition for renal tubular secretion via OCT2 and MATE transporters reduces procainamide clearance.
What to do
Monitor ECG and procainamide/NAPA concentrations and renal function when the combination is used; reduce the procainamide dose if levels or QRS/QT intervals rise.
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 Metformin
Frequently asked questions
Can I take Metformin with Procainamide?
MediHelp rates the interaction as moderate. Metformin and Procainamide 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 are eliminated by renal tubular secretion, so metformin may raise procainamide and its metabolite NAPA levels. This could increase the risk of arrhythmia or other procainamide toxicity, particularly in renal impairment.
How serious is the interaction between Metformin and Procainamide?
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 ECG and procainamide/NAPA concentrations and renal function when the combination is used; reduce the procainamide dose if levels or QRS/QT intervals rise.
What other medicines interact with Metformin?
MediHelp also lists interactions of Metformin with, for example, Contrast media, Diatrizoate meglumine / diatrizoate, Diatrizoate. The full list is on the Metformin page.
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