Drug interactions
Captopril-hydrochlorothiazide + Formoterol
Severity: Moderate
Captopril-hydrochlorothiazide and Formoterol: 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
Formoterol and hydrochlorothiazide can each lower serum potassium. Together they may produce clinically important hypokalemia, which increases arrhythmia risk, especially with high doses of formoterol or in patients with hypoxia.
What this interaction means in plain words
Captopril-hydrochlorothiazide and Formoterol 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-hydrochlorothiazide belongs to Cardiovascular; Formoterol belongs to Respiratory.
Why it happens
Beta-2 agonism shifts potassium into cells while thiazides increase renal potassium loss, giving additive hypokalemia.
What to do
Monitor serum potassium and magnesium, particularly at treatment start and in patients with severe asthma or COPD. Replace potassium as needed; the ACE inhibitor component partly offsets losses.
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-hydrochlorothiazide
- Aliskiren + Captopril-hydrochlorothiazide Contraindicated
- Captopril-hydrochlorothiazide + Dofetilide Contraindicated
- Captopril-hydrochlorothiazide + Sacubitril / valsartan Contraindicated
- Aceclofenac + Captopril-hydrochlorothiazide Major
- Aldesleukin + Captopril-hydrochlorothiazide Major
- Amifostine + Captopril-hydrochlorothiazide Major
Other interactions of Formoterol
- Adagrasib + Formoterol Major
- Amiodarone + Formoterol Major
- Amisulpride + Formoterol Major
- Amitriptyline + Formoterol Major
- Amoxapine + Formoterol Major
- Arformoterol + Formoterol Major
Frequently asked questions
Can I take Captopril-hydrochlorothiazide with Formoterol?
MediHelp rates the interaction as moderate. Captopril-hydrochlorothiazide and Formoterol 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. Formoterol and hydrochlorothiazide can each lower serum potassium. Together they may produce clinically important hypokalemia, which increases arrhythmia risk, especially with high doses of formoterol or in patients with hypoxia.
How serious is the interaction between Captopril-hydrochlorothiazide and Formoterol?
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 serum potassium and magnesium, particularly at treatment start and in patients with severe asthma or COPD. Replace potassium as needed; the ACE inhibitor component partly offsets losses.
What other medicines interact with Captopril-hydrochlorothiazide?
MediHelp also lists interactions of Captopril-hydrochlorothiazide with, for example, Aliskiren, Dofetilide, Sacubitril / valsartan. The full list is on the Captopril-hydrochlorothiazide page.
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