Isoniazid and Trimipramine interaction
Isoniazid and Trimipramine: the Trimipramine prescribing label flags 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 Trimipramine label · effective 2026-03-17
CONTRAINDICATIONS Monoamine Oxidase Inhibitors (MAOIs) The use of MAOIs intended to treat psychiatric disorders with trimipramine capsules or within 14 days of stopping treatment with trimipramine capsules is contraindicated because of an increased risk of serotonin syndrome.
The use of trimipramine capsules within 14 days of stopping an MAOI intended to treat psychiatric disorders is also contraindicated (see WARNINGS and DOSAGE AND ADMINISTRATION ).
Starting trimipramine capsules in a patient who is being treated with MAOIs such as linezolid or intravenous methylene blue is also contraindicated because of an increased risk of serotonin syndrome (see WARNINGS and DOSAGE AND ADMINISTRATION ).
The concomitant use of trimipramine capsules with MAOIs intended to treat psychiatric disorders is contraindicated.
Trimipramine capsules should be discontinued before initiating treatment with the MAOI (see CONTRAINDICATIONS and DOSAGE AND ADMINISTRATION ).
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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.