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Causality: well established
Causality assessment · Causality: well established
Dapsone and Methaemoglobinaemia: 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.
Dapsone ↔ Methaemoglobinaemia
n=480 co-reports · PRR 522.3 · ROR 547.0
Dapsone oxidises haemoglobin and causes dose-dependent methaemoglobinaemia, which can be severe and even fatal; 480 co-reports give an extreme PRR of 522.3. The label warns of this effect and advises monitoring, especially at higher doses.
Regulatory basis: dapsone prescribing information — methaemoglobinaemia; clinical monitoring and supportive care.
| Bradford Hill viewpoint | Status | Note |
|---|---|---|
| Temporality (necessary) | met | Hours to days |
| Strength | met | PRR 522.3, an extreme signal |
| Consistency | met | Reproduced across cohorts |
| Specificity | met | Fairly specific to dapsone |
| Biological gradient | met | Clear dose dependence |
| Plausibility | met | Known haem-oxidation mechanism |
| Coherence | met | Fits dapsone's redox toxicity |
| Experiment | n/a | Not a routine trial endpoint |
| Analogy | met | Analogous to other oxidant drugs |
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 dapsone captured methaemoglobinaemia as a tracked adverse event in a usable structure. Methaemoglobin is not a standard trial safety endpoint.