Amitriptyline and Dofetilide interaction
Amitriptyline and Dofetilide: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Dofetilide label · effective 2026-04-24
Use with Drugs that Prolong QT Interval and Antiarrhythmic Agents The use of dofetilide in conjunction with other drugs that prolong the QT interval has not been studied and is not recommended.
Such drugs include phenothiazines, cisapride, bepridil, tricyclic antidepressants, certain oral macrolides, and certain fluoroquinolones.
…hydrochlorothiazide (alone or in combinations such as with triamterene) (see CONTRAINDICATIONS ), other cardiovascular drugs (especially verapamil – see CONTRAINDICATIONS ), phenothiazines, and tricyclic antidepressants (see WARNINGS ).If a patient is taking dofetilide and requires anti-ulcer therapy, omeprazole, ranitidine, or antacids (aluminum and magnesium hydroxides)…
From the Amitriptyline (Amitriptyline Hydrochloride) label · effective 2025-11-25
The drugs that inhibit cytochrome P450 2D6 include some that are not metabolized by the enzyme (quinidine; cimetidine) and many that are substrates for P450 2D6 (many other antidepressants, phenothiazines, and the Type 1C antiarrhythmics propafenone and flecainide).
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Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.