Duloxetine and Isoniazid interaction
Duloxetine and Isoniazid: the Duloxetine 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 Duloxetine (Cymbalta) label · effective 2025-07-21
The use of MAOIs intended to treat psychiatric disorders with CYMBALTA or within 5 days of stopping treatment with CYMBALTA is contraindicated because of an increased risk of serotonin syndrome.
The use of CYMBALTA within 14 days of stopping an MAOI intended to treat psychiatric disorders is contraindicated [see Dosage and Administration ( 2.8 ) and Warnings and Precautions ( 5.4 )] .
Starting CYMBALTA 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 ( 2.9 ) and Warnings and Precautions ( 5.4 )] .
Concomitant use of an MAOI antidepressant with CYMBALTA is contraindicated Use of CYMBALTA within 14 days of stopping an MAOI antidepressant is contraindicated In linezolid- or intravenous methylene blue-treated patients, initiation of CYMBALTA is contraindicated ( 4 )
The concomitant use of CYMBALTA with MAOIs is contraindicated.
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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.