Drug interactions
Formoterol + Hydrochlorothiazide-losartan
Severity: Moderate
Formoterol and Hydrochlorothiazide-losartan: 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, a beta-2 agonist, moves potassium into cells, and hydrochlorothiazide increases renal potassium loss. The combination may cause hypokalemia, especially with high doses of formoterol or during acute asthma or COPD exacerbations.
What this interaction means in plain words
Formoterol and Hydrochlorothiazide-losartan 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 belongs to Respiratory; Hydrochlorothiazide-losartan belongs to Cardiovascular.
Why it happens
Additive hypokalemia from beta-2-mediated cellular potassium uptake and thiazide kaliuresis.
What to do
Monitor serum potassium in patients with severe airway disease or on high doses. Replace potassium if levels are low.
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 Hydrochlorothiazide-losartan
- Aliskiren + Hydrochlorothiazide-losartan Contraindicated
- Dofetilide + Hydrochlorothiazide-losartan Contraindicated
- Hydrochlorothiazide-losartan + Sparsentan Contraindicated
- Aceclofenac + Hydrochlorothiazide-losartan Major
- Aldesleukin + Hydrochlorothiazide-losartan Major
- Amifostine + Hydrochlorothiazide-losartan 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 Formoterol with Hydrochlorothiazide-losartan?
MediHelp rates the interaction as moderate. Formoterol and Hydrochlorothiazide-losartan 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, a beta-2 agonist, moves potassium into cells, and hydrochlorothiazide increases renal potassium loss. The combination may cause hypokalemia, especially with high doses of formoterol or during acute asthma or COPD exacerbations.
How serious is the interaction between Formoterol and Hydrochlorothiazide-losartan?
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 in patients with severe airway disease or on high doses. Replace potassium if levels are low.
What other medicines interact with Hydrochlorothiazide-losartan?
MediHelp also lists interactions of Hydrochlorothiazide-losartan with, for example, Aliskiren, Dofetilide, Sparsentan. The full list is on the Hydrochlorothiazide-losartan page.
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