Drug interactions
Formoterol + Methadone
Severity: Moderate
Formoterol and Methadone: 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 methadone and high-dose beta-2 agonists such as formoterol can prolong the QTc interval, and formoterol may also lower serum potassium. Together they may add to the risk of QT prolongation and torsades de pointes, especially with other risk factors.
What this interaction means in plain words
Formoterol and Methadone 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; Methadone belongs to Musculoskeletal.
Why it happens
Additive QTc prolongation, with formoterol-induced hypokalemia further increasing arrhythmia susceptibility.
What to do
Obtain a baseline ECG and monitor QTc after starting or increasing doses, particularly in patients with cardiac disease. Check and correct potassium and magnesium levels.
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 Methadone
- Alvimopan + Methadone Contraindicated
- Calcium / magnesium / potassium / sodium oxybates + Methadone Contraindicated
- Droperidol + Methadone Contraindicated
- Ibutilide + Methadone Contraindicated
- Isocarboxazid + Methadone Contraindicated
- Lefamulin + Methadone Contraindicated
Frequently asked questions
Can I take Formoterol with Methadone?
MediHelp rates the interaction as moderate. Formoterol and Methadone 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 methadone and high-dose beta-2 agonists such as formoterol can prolong the QTc interval, and formoterol may also lower serum potassium. Together they may add to the risk of QT prolongation and torsades de pointes, especially with other risk factors.
How serious is the interaction between Formoterol and Methadone?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Obtain a baseline ECG and monitor QTc after starting or increasing doses, particularly in patients with cardiac disease. Check and correct potassium and magnesium levels.
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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