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Causality: well established
Causality assessment · Causality: well established
Fluvoxamine 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.
Fluvoxamine ↔ Serotonin syndrome
n=81 co-reports · PRR 37.3 · ROR 38.6
Fluvoxamine is an SSRI that, like the class, can cause serotonin syndrome when combined with other serotonergic agents — 81 co-reports here (PRR 37.3). It is also a potent CYP1A2 and CYP2C19 inhibitor, so it raises levels of co-prescribed drugs (including some that are themselves serotonergic or QT-prolonging), amplifying the risk. MAOI combinations are contraindicated.
Regulatory basis: fluvoxamine prescribing information — serotonin syndrome; CYP1A2/2C19 inhibition; contraindicated with MAOIs.
| Bradford Hill viewpoint | Status | Note |
|---|---|---|
| Temporality (necessary) | met | Onset within hours to days |
| Strength | met | PRR 37.3, large |
| Consistency | met | Reproduced across serotonergic drugs |
| Specificity | partial | Not specific within the class |
| Biological gradient | met | Worse with added serotonergic load |
| Plausibility | met | Excess-serotonin mechanism |
| Coherence | met | Fits SSRI pharmacology |
| Experiment | met | Case series and dechallenge support it |
| Analogy | met | Analogous to other SSRI/MAOI 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 fluvoxamine-maleate captured serotonin syndrome as a tracked adverse event in a usable structure. Serotonin syndrome usually requires drug combinations and rarely appears in single-agent trial arms, so trials did not capture it as a coded event.