Drug interactions
Nortriptyline + Trimethoprim
Severity: Minor
Nortriptyline and Trimethoprim: minor 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
Trimethoprim has been associated with rare QT prolongation, and nortriptyline can also lengthen the QT interval. The combined risk is usually small but matters in patients with other arrhythmia risk factors.
What this interaction means in plain words
Nortriptyline and Trimethoprim have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Nortriptyline belongs to Central Nervous System; Trimethoprim belongs to Anti Bacterial.
Why it happens
Possible additive QT prolongation; evidence for trimethoprim alone is limited.
What to do
No routine action is needed in low-risk patients, but check the ECG and electrolytes in those with heart disease or other QT-prolonging drugs.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Nortriptyline
- Disopyramide + Nortriptyline Contraindicated
- Dofetilide + Nortriptyline Contraindicated
- Dronedarone + Nortriptyline Contraindicated
- Ibutilide + Nortriptyline Contraindicated
- Isocarboxazid + Nortriptyline Contraindicated
- Methylene blue + Nortriptyline Contraindicated
Other interactions of Trimethoprim
Frequently asked questions
Can I take Nortriptyline with Trimethoprim?
MediHelp rates the interaction as minor. Nortriptyline and Trimethoprim have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Trimethoprim has been associated with rare QT prolongation, and nortriptyline can also lengthen the QT interval. The combined risk is usually small but matters in patients with other arrhythmia risk factors.
How serious is the interaction between Nortriptyline and Trimethoprim?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No routine action is needed in low-risk patients, but check the ECG and electrolytes in those with heart disease or other QT-prolonging drugs.
What other medicines interact with Nortriptyline?
MediHelp also lists interactions of Nortriptyline with, for example, Disopyramide, Dofetilide, Dronedarone. The full list is on the Nortriptyline page.
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