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Causality: well established
Causality assessment · Causality: well established
Carbamazepine and Agranulocytosis: 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.
Carbamazepine ↔ Agranulocytosis
n=184 co-reports · PRR 3.2 · ROR 3.2
Carbamazepine can cause blood dyscrasias including agranulocytosis and aplastic anaemia; 184 co-reports give PRR 3.2. The risk is idiosyncratic and potentially fatal, so the label advises immediate blood counts if fever, sore throat or infection develops.
Regulatory basis: carbamazepine (Tegretol) prescribing information — aplastic anaemia and agranulocytosis; prompt blood-count monitoring.
| Bradford Hill viewpoint | Status | Note |
|---|---|---|
| Temporality (necessary) | met | Idiosyncratic, weeks to months |
| Strength | met | PRR 3.2 with 184 co-reports |
| Consistency | met | Reproduced across reports |
| Specificity | met | Fairly specific to carbamazepine |
| Biological gradient | not established | Not clearly dose-related |
| Plausibility | met | Plausible marrow toxicity |
| Coherence | met | Fits aromatic anticonvulsant dyscrasias |
| Experiment | n/a | Too rare for trial detection |
| Analogy | met | Analogous to phenytoin and valproate cytopenias |
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 carbamazepine captured agranulocytosis as a tracked adverse event in a usable structure. Randomised epilepsy trials were far too small and short to capture idiosyncratic agranulocytosis.