Drug interactions
Chlorthalidone + Formoterol
Severity: Moderate
Chlorthalidone 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
Both formoterol and the thiazide-like diuretic chlorthalidone can lower serum potassium. Used together, particularly at higher formoterol doses or in patients with heart disease, hypokalemia may be more pronounced and can promote arrhythmias.
What this interaction means in plain words
Chlorthalidone 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.
Chlorthalidone belongs to Cardiovascular; Formoterol belongs to Respiratory.
Why it happens
Additive hypokalemia: beta-2 agonism shifts potassium into cells while chlorthalidone increases renal potassium loss.
What to do
Monitor serum potassium and magnesium periodically, especially at treatment start or dose increases. Replace potassium as needed and be more vigilant in patients with cardiac disease or other hypokalemic risks.
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 Formoterol
- Adagrasib + Formoterol Major
- Amiodarone + Formoterol Major
- Amisulpride + Formoterol Major
- Amitriptyline + Formoterol Major
- Amoxapine + Formoterol Major
- Arformoterol + Formoterol Major
Other interactions of Chlorthalidone
Frequently asked questions
Can I take Chlorthalidone with Formoterol?
MediHelp rates the interaction as moderate. Chlorthalidone 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. Both formoterol and the thiazide-like diuretic chlorthalidone can lower serum potassium. Used together, particularly at higher formoterol doses or in patients with heart disease, hypokalemia may be more pronounced and can promote arrhythmias.
How serious is the interaction between Chlorthalidone 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 periodically, especially at treatment start or dose increases. Replace potassium as needed and be more vigilant in patients with cardiac disease or other hypokalemic risks.
What other medicines interact with Formoterol?
MediHelp also lists interactions of Formoterol with, for example, Adagrasib, Amiodarone, Amisulpride. The full list is on the Formoterol page.
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