Drug interactions
Amitriptyline + Diltiazem
Severity: Moderate
Amitriptyline and Diltiazem: 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
Diltiazem may increase amitriptyline concentrations, raising anticholinergic, sedative and cardiac effects. Additive hypotension and conduction effects may also occur.
What this interaction means in plain words
Amitriptyline and Diltiazem 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.
Amitriptyline belongs to Central Nervous System; Diltiazem belongs to Cardiovascular.
Why it happens
Diltiazem inhibits CYP3A4, which contributes to amitriptyline metabolism, with additive hypotensive effects.
What to do
Monitor blood pressure, ECG and anticholinergic effects, and lower the amitriptyline dose if toxicity appears.
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 Diltiazem
- Diltiazem + Flibanserin Contraindicated
- Diltiazem + Ivabradine Contraindicated
- Diltiazem + Lomitapide Contraindicated
- Diltiazem + Lonafarnib Contraindicated
- Acebutolol + Diltiazem Major
- Alfentanil + Diltiazem Major
Other interactions of Amitriptyline
- Amitriptyline + Isocarboxazid Contraindicated
- Amitriptyline + Methylene blue Contraindicated
- Amitriptyline + Phenelzine Contraindicated
- Amitriptyline + Pimozide Contraindicated
- Amitriptyline + Procarbazine Contraindicated
- Amitriptyline + Safinamide Contraindicated
Frequently asked questions
Can I take Amitriptyline with Diltiazem?
MediHelp rates the interaction as moderate. Amitriptyline and Diltiazem 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. Diltiazem may increase amitriptyline concentrations, raising anticholinergic, sedative and cardiac effects. Additive hypotension and conduction effects may also occur.
How serious is the interaction between Amitriptyline and Diltiazem?
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 blood pressure, ECG and anticholinergic effects, and lower the amitriptyline dose if toxicity appears.
What other medicines interact with Diltiazem?
MediHelp also lists interactions of Diltiazem with, for example, Flibanserin, Ivabradine, Lomitapide. The full list is on the Diltiazem page.
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