Amitriptyline and Isoniazid interaction
Amitriptyline and Isoniazid: the Amitriptyline prescribing label 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 Amitriptyline (Amitriptyline Hydrochloride) label · effective 2025-11-25
It should not be given concomitantly with monoamine oxidase inhibitors.
When it is desired to replace a monoamine oxidase inhibitor with amitriptyline hydrochloride, a minimum of 14 days should be allowed to elapse after the former is discontinued.
Monoamine oxidase inhibitors – see CONTRAINDICATIONS section.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
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.