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Causality: well established
Causality assessment · Causality: well established
Chlorpromazine and Neuroleptic malignant 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.
Chlorpromazine ↔ Neuroleptic malignant syndrome
n=294 co-reports · PRR 74.9 · ROR 78.1
Chlorpromazine is a first-generation antipsychotic; dopamine D2 blockade in the hypothalamus and basal ganglia underlies neuroleptic malignant syndrome — hyperthermia, rigidity, autonomic instability, and raised creatine kinase — 294 co-reports here (PRR 74.9). NMS is rare but potentially fatal and is why any antipsychotic requires vigilance for the syndrome, with immediate drug withdrawal and supportive care.
Regulatory basis: chlorpromazine prescribing information — neuroleptic malignant syndrome; antipsychotic class warning.
| Bradford Hill viewpoint | Status | Note |
|---|---|---|
| Temporality (necessary) | partial | Onset over days of therapy or dose change |
| Strength | met | PRR 74.9, very large |
| Consistency | met | Reproduced across antipsychotics |
| Specificity | not established | Not specific to any one antipsychotic |
| Biological gradient | met | More likely with rapid dose escalation |
| Plausibility | met | Central dopamine-blockade mechanism |
| Coherence | met | Fits the pharmacology |
| Experiment | n/a | Too rare for trial detection |
| Analogy | met | Analogous across the antipsychotic class |
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 chlorpromazine captured neuroleptic malignant syndrome as a tracked adverse event in a usable structure. NMS is too rare to appear in the trial populations that studied chlorpromazine, so trials did not capture it as a coded event.