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Causality: well established
Causality assessment · Causality: well established
Buspirone and Serotonin syndrome: is the FAERS signal real?
A written Bradford Hill assessment of one drug–event pair. The grade is a judgement about the signal, not a statement that this drug causes this event in any one person; FAERS counts are reports, not rates.
Buspirone ↔ Serotonin syndrome
n=119 co-reports · PRR 12.0 · ROR 12.1
Buspirone is a partial 5-HT1A agonist used for anxiety; it is serotonergic, and combining it with SSRIs, MAOIs, or other serotonergic drugs can precipitate serotonin syndrome (119 co-reports, PRR 12.0). The label warns against MAOI co-administration, and the risk is dose-related with respect to total serotonergic load.
Regulatory basis: buspirone prescribing information — serotonin syndrome; contraindicated with MAOIs.
| Bradford Hill viewpoint | Status | Note |
|---|---|---|
| Temporality (necessary) | met | Onset within hours to days of combination |
| Strength | met | PRR 12.0, moderate |
| Consistency | met | Reproduced across serotonergic drugs |
| Specificity | partial | Not specific within serotonergic drugs |
| Biological gradient | met | Worse with higher combined load |
| Plausibility | met | Excess-serotonin mechanism |
| Coherence | met | Fits the pharmacology |
| Experiment | met | Case series and dechallenge support it |
| Analogy | met | Analogous to other serotonergic combinations |
This table is this page's own qualitative read of the literature cited above, not an automated or citation-gated assessment — see the note at the bottom of this page.
✗ No ClinicalTrials.gov results-posting trial in the top search hits for buspirone-hydrochloride captured serotonin syndrome as a tracked adverse event in a usable structure. Serotonin syndrome is combination-triggered and rarely appears in single-agent trial arms, so trials did not capture it as a coded event.