Drug interactions
Maprotiline + Trimethoprim
Severity: Moderate
Maprotiline and Trimethoprim: 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
Maprotiline prolongs the QT interval, and trimethoprim has been associated with QT prolongation in a few reports. Combined use may add to arrhythmia risk, most relevant in patients with electrolyte disturbance, renal impairment or heart disease.
What this interaction means in plain words
Maprotiline and Trimethoprim 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.
Maprotiline belongs to Central Nervous System; Trimethoprim belongs to Anti Bacterial.
Why it happens
Possible additive prolongation of cardiac repolarization; the trimethoprim effect is weakly established.
What to do
Check ECG and potassium in at-risk patients and monitor QTc during co-therapy. Consider an alternative antibiotic if the QTc is markedly prolonged.
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 Maprotiline
- Arsenic trioxide + Maprotiline Contraindicated
- Disopyramide + Maprotiline Contraindicated
- Dofetilide + Maprotiline Contraindicated
- Ibutilide + Maprotiline Contraindicated
- Isocarboxazid + Maprotiline Contraindicated
- Maprotiline + Methylene blue Contraindicated
Other interactions of Trimethoprim
Frequently asked questions
Can I take Maprotiline with Trimethoprim?
MediHelp rates the interaction as moderate. Maprotiline and Trimethoprim 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. Maprotiline prolongs the QT interval, and trimethoprim has been associated with QT prolongation in a few reports. Combined use may add to arrhythmia risk, most relevant in patients with electrolyte disturbance, renal impairment or heart disease.
How serious is the interaction between Maprotiline and Trimethoprim?
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 ECG and potassium in at-risk patients and monitor QTc during co-therapy. Consider an alternative antibiotic if the QTc is markedly prolonged.
What other medicines interact with Maprotiline?
MediHelp also lists interactions of Maprotiline with, for example, Arsenic trioxide, Disopyramide, Dofetilide. The full list is on the Maprotiline page.
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