Buspirone and Phenelzine interaction
Buspirone and Phenelzine: 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 Buspirone (Buspirone Hydrochloride) label · effective 2026-03-18
The use of monoamine oxidase inhibitors (MAOIs) intended to treat depression with buspirone or within 14 days of stopping treatment with buspirone is contraindicated because of an increased risk of serotonin syndrome and/or elevated blood pressure.
The use of buspirone within 14 days of stopping an MAOI intended to treat depression is also contraindicated.
Starting buspirone in a patient who is being treated with reversible MAOIs such as linezolid or intravenous methylene blue is also contraindicated because of an increased risk of serotonin syndrome.
Serotonin Syndrome The development of a potentially life-threatening serotonin syndrome has been reported with SNRIs SSRIs, and other serotonergic drugs, including buspirone, alone but particularly with concomitant use of other serotonergic drugs (including triptans), with drugs that impair metabolism of serotonin (in particular, MAOIs, including reversible MAOIs…
The concomitant use of buspirone with MAOIs intended to treat depression is contraindicated.
From the Phenelzine (phenelzine sulfate) label · effective 2026-05-21
…Generic Name Follows: pargyline hydrochloride pargyline hydrochloride and methylclothiazide furazolidone isocarboxazid procarbazine tranylcypromine Phenelzine sulfate should also not be used in combination with buspirone HCl, since several cases of elevated blood pressure have been reported in patients taking MAO inhibitors who were then given buspirone HCl.
At least 14 days should elapse between the discontinuation of phenelzine sulfate and the institution of another antidepressant or buspirone HCl, or the discontinuation of another MAO inhibitor and the institution of phenelzine sulfate.
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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.