Drug interactions
Dichlorphenamide + Methadone
Severity: Moderate
Dichlorphenamide 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
Dichlorphenamide causes potassium loss and metabolic acidosis, and hypokalemia raises the risk of QT prolongation and torsades de pointes in patients taking methadone. The risk is greatest with higher methadone doses or other QT risk factors.
What this interaction means in plain words
Dichlorphenamide 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.
Dichlorphenamide belongs to Miscellaneous; Methadone belongs to Musculoskeletal.
Why it happens
Carbonic anhydrase inhibition causes renal potassium wasting, and the resulting hypokalemia adds to methadone's QT-prolonging effect.
What to do
Check serum potassium and bicarbonate at baseline and periodically, and correct deficits promptly. Obtain an ECG if other QT risk factors are present.
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 Methadone
- Alvimopan + Methadone Contraindicated
- Calcium / magnesium / potassium / sodium oxybates + Methadone Contraindicated
- Droperidol + Methadone Contraindicated
- Ibutilide + Methadone Contraindicated
- Isocarboxazid + Methadone Contraindicated
- Lefamulin + Methadone Contraindicated
Other interactions of Dichlorphenamide
Frequently asked questions
Can I take Dichlorphenamide with Methadone?
MediHelp rates the interaction as moderate. Dichlorphenamide 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. Dichlorphenamide causes potassium loss and metabolic acidosis, and hypokalemia raises the risk of QT prolongation and torsades de pointes in patients taking methadone. The risk is greatest with higher methadone doses or other QT risk factors.
How serious is the interaction between Dichlorphenamide 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: Check serum potassium and bicarbonate at baseline and periodically, and correct deficits promptly. Obtain an ECG if other QT risk factors are present.
What other medicines interact with Methadone?
MediHelp also lists interactions of Methadone with, for example, Alvimopan, Calcium / magnesium / potassium / sodium oxybates, Droperidol. The full list is on the Methadone page.
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