Isoniazid and Venlafaxine interaction
Isoniazid and Venlafaxine: the Venlafaxine 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 Venlafaxine (Venlafaxine Hydrochloride) label · effective 2025-01-31
Serotonin Syndrome and MAOIs: Do not use MAOI’s intended to treat psychiatric disorders with Venlafaxine Extended Release Tablets or within 7 days of stopping treatment with Venlafaxine Extended Release Tablets.
Do not use Venlafaxine Extended Release Tablets within 14 days of stopping an MAOI intended to treat psychiatric disorders.
Monoamine Oxidase Inhibitors (MAOIs) The use of MAOI’s intended to treat psychiatric disorders with Venlafaxine Extended Release Tablets or within 7 days of stopping treatment with Venlafaxine Extended Release Tablets is contraindicated because of an increased risk of serotonin syndrome.
The use of Venlafaxine Extended Release Tablets within 14 days of stopping, an MAOI intended to treat psychiatric disorders is also contraindicated [see Dosage and Administration ( 2.6 ), and Warnings and Precautions ( 5.2 )] .
Starting Venlafaxine Extended Release Tablets 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 Dosage and Administration ( 2.7 ) and Warnings and Precautions ( 5.2 )] .
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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.