Drug interactions
Captopril + Methyclothiazide
Severity: Moderate
Captopril and Methyclothiazide: 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
Thiazide diuretics combined with ACE inhibitors produce additive blood pressure lowering, and first-dose hypotension may occur in volume-depleted patients. Renal function may deteriorate, especially with sodium or volume depletion. The combination is also commonly used therapeutically.
What this interaction means in plain words
Captopril and Methyclothiazide 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
Diuretic-induced volume depletion activates the renin-angiotensin system, so ACE inhibition produces exaggerated hypotension and reduced glomerular filtration.
What to do
Monitor blood pressure, serum creatinine and electrolytes after initiation and dose changes; consider lowering the diuretic dose before starting captopril in volume-depleted patients.
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
Frequently asked questions
Can I take Captopril with Methyclothiazide?
MediHelp rates the interaction as moderate. Captopril and Methyclothiazide 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. Thiazide diuretics combined with ACE inhibitors produce additive blood pressure lowering, and first-dose hypotension may occur in volume-depleted patients. Renal function may deteriorate, especially with sodium or volume depletion. The combination is also commonly used therapeutically.
How serious is the interaction between Captopril and Methyclothiazide?
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 blood pressure, serum creatinine and electrolytes after initiation and dose changes; consider lowering the diuretic dose before starting captopril in volume-depleted patients.
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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