Buspirone and Ondansetron interaction
Buspirone and Ondansetron: 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
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…
From the Ondansetron label · effective 2026-04-16
Patients should be monitored for the emergence of serotonin syndrome, especially with concomitant use of Ondansetron Injection and other serotonergic drugs.
Patients should be informed of the increased risk of serotonin syndrome, especially if Ondansetron Injection is used concomitantly with other serotonergic drugs [see Drug Interactions (7.5 ), Overdosage (10) ] .
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.