Drug interactions
Amitriptyline + Mefloquine
Severity: Major
Amitriptyline and Mefloquine: major 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
Mefloquine and amitriptyline each can lengthen the QTc interval, and together they may increase the chance of ventricular arrhythmias including torsades de pointes. Tricyclic antidepressants may also lower the seizure threshold, and mefloquine carries neuropsychiatric effects as well.
What this interaction means in plain words
Amitriptyline and Mefloquine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Amitriptyline belongs to Central Nervous System; Mefloquine belongs to Anti Parasitic.
Why it happens
Additive QT prolongation via hERG potassium channel blockade, with overlapping neuropsychiatric and seizure-threshold effects.
What to do
Prefer an alternative antimalarial or antidepressant. If both are required, check a baseline ECG, correct electrolytes and monitor for palpitations, syncope and neuropsychiatric symptoms.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Mefloquine
- Arsenic trioxide + Mefloquine Contraindicated
- Dronedarone + Mefloquine Contraindicated
- Ibutilide + Mefloquine Contraindicated
- Levoketoconazole + Mefloquine Contraindicated
- Mefloquine + Nilotinib Contraindicated
- Mefloquine + Pimozide Contraindicated
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 Mefloquine?
MediHelp rates the interaction as major. Amitriptyline and Mefloquine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Mefloquine and amitriptyline each can lengthen the QTc interval, and together they may increase the chance of ventricular arrhythmias including torsades de pointes. Tricyclic antidepressants may also lower the seizure threshold, and mefloquine carries neuropsychiatric effects as well.
How serious is the interaction between Amitriptyline and Mefloquine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Prefer an alternative antimalarial or antidepressant. If both are required, check a baseline ECG, correct electrolytes and monitor for palpitations, syncope and neuropsychiatric symptoms.
What other medicines interact with Mefloquine?
MediHelp also lists interactions of Mefloquine with, for example, Arsenic trioxide, Dronedarone, Ibutilide. The full list is on the Mefloquine page.
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