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Causality: well established
Causality assessment · Causality: well established
Tramadol and Seizures: 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.
Tramadol ↔ Seizures
n=467 co-reports · PRR 2.3 · ROR 2.3
Tramadol lowers the seizure threshold, and this risk rises with higher doses, with rapid dose escalation, and when it is combined with other seizure-threshold-lowering drugs such as SSRIs, tricyclics, or antipsychotics. The effect is genuine and dose-related rather than idiosyncratic, and it is why tramadol is used cautiously in people with epilepsy. The 467 co-reports (PRR 2.3) reflect both the real effect and tramadol's wide prescription as an analgesic.
Regulatory basis: tramadol prescribing information (seizure risk; caution with other serotonergic or pro-convulsant drugs).
| Bradford Hill viewpoint | Status | Note |
|---|---|---|
| Temporality (necessary) | met | Seizures occur during treatment and risk falls after dose reduction or withdrawal |
| Strength | partial | PRR 2.3 on a moderate co-report count — a modest but real signal |
| Consistency | met | Reproduced across case series and observational data |
| Specificity | met | A recognised tramadol effect, less typical of other opioids |
| Biological gradient | met | Dose-related and worse with interacting drugs |
| Plausibility | met | Monoamine-reuptake inhibition and opioid effects are proposed |
| Coherence | met | Coheres with the labelled seizure caution |
| Experiment | partial | Dechallenge (dose reduction/withdrawal) lowers risk; no randomized trial |
| Analogy | met | Analogous to seizures from bupropion and tricyclic antidepressants |
This page's own qualitative read, not an automated/citation-gated assessment.
✗ No ClinicalTrials.gov results-posting trial in the top search hits for tramadol captured seizures as a coded event; the risk is characterised through case series and observational data rather than a trial AE table.