← All causality assessments
Causality: well established
Causality assessment · Causality: well established
Trazodone and Priapism: 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.
Trazodone ↔ Priapism
n=34 co-reports · PRR 13.3 · ROR 13.4
Trazodone is the antidepressant most associated with priapism, a prolonged, painful erection that is a urological emergency — an effect related to its alpha-adrenergic blocking action. It is uncommon but well recognised and can occur at therapeutic doses, so patients are warned to seek urgent help. The 34 co-reports (PRR 13.3) are small because priapism is rare and under-reported, but the association is distinctive and specific.
Regulatory basis: trazodone prescribing information (priapism warning). Established trazodone-priapism literature.
| Bradford Hill viewpoint | Status | Note |
|---|---|---|
| Temporality (necessary) | met | Priapism occurs during treatment and is treated as an emergency by withdrawal and intervention |
| Strength | partial | PRR 13 on a small co-report count |
| Consistency | met | Reproduced across decades of trazodone case reports |
| Specificity | met | A distinctive trazodone effect, unusual for other antidepressants |
| Biological gradient | partial | Not clearly dose-related; can occur at therapeutic doses |
| Plausibility | met | Alpha-adrenergic blockade in penile vasculature is the proposed mechanism |
| Coherence | met | Coheres with the labelled warning to seek urgent care |
| Experiment | partial | Dechallenge (withdrawal) plus urological treatment resolves it; no randomized trial |
| Analogy | met | Analogous to priapism from some other alpha-blocking drugs |
This page's own qualitative read, not an automated/citation-gated assessment.
✗ No ClinicalTrials.gov results-posting trial in the top search hits for trazodone captured priapism; it is a rare emergency identified through case reports rather than a trial AE table.