Drug interactions
Methyclothiazide + Triamterene
Severity: Minor
Methyclothiazide and Triamterene: minor 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
Thiazides cause potassium and magnesium loss while triamterene retains potassium, so the combination is used deliberately to keep potassium balanced in hypertension and edema. Overall potassium may still drift either way, and hyponatremia and volume depletion may occur.
What this interaction means in plain words
Methyclothiazide and Triamterene have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Why it happens
Opposing effects on distal tubular potassium handling: thiazide-induced kaliuresis versus triamterene sodium channel blockade.
What to do
Check serum potassium, sodium and renal function after starting and periodically thereafter.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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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
Frequently asked questions
Can I take Methyclothiazide with Triamterene?
MediHelp rates the interaction as minor. Methyclothiazide and Triamterene have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Thiazides cause potassium and magnesium loss while triamterene retains potassium, so the combination is used deliberately to keep potassium balanced in hypertension and edema. Overall potassium may still drift either way, and hyponatremia and volume depletion may occur.
How serious is the interaction between Methyclothiazide and Triamterene?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Check serum potassium, sodium and renal function after starting and periodically thereafter.
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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