Overview
- Researchers reported on Wednesday that a combination of chlorpromazine and promethazine sharply lowered core temperature and reduced brain injury after experimentally induced stroke in mice and in rhesus macaques.
- The team then ran a randomized, placebo‑controlled phase I trial of 32 acute ischemic stroke patients that found the drug regimen to be safe and to produce metabolic biomarkers but ineffective at the doses and infusion schedule used.
- Only the highest dose in the human trial reliably lowered patients’ body temperature, and all dose groups showed signals of reduced metabolism such as lower oxygen use without major adverse events in this small safety study.
- Laboratory work indicates the drugs cool the body both by dilating skin blood vessels to shed heat and by lowering cellular oxygen consumption, a mechanism that could extend the time neurons survive before blood flow is restored.
- Authors caution that past trials in the 1980s were stopped because high doses caused dangerous drops in blood pressure, and they say future phase 2 studies must optimize dose and infusion speed while closely monitoring hypotension and other risks.