Drug Combination Cooled Body Temperature After Stroke in Animals and Humans but Showed No Reduction in Brain Damage

A combination of promethazine and chlorpromazine cooled core body temperature in mice and rhesus monkeys after induced strokes and reduced brain damage, @NewScientist reported. Treated rhesus monkeys also showed better limb use than untreated animals. The same drug combination suppressed glucose metabolism in brain cells of the treated animals.

Researchers next ran a clinical trial with 32 people admitted to hospital immediately after stroke. Participants received either the promethazine-chlorpromazine combination or placebo in addition to standard clot-removal therapy. The treatment lowered patients’ core body temperature by 0.3 °C but produced no measurable reduction in stroke damage.

Infusions in the trial were administered over 12 hours. A follow-up clinical trial will test one-hour infusions of the same combination. Promethazine is a sedating antihistamine used for hay fever and sleep assistance.

Chlorpromazine is an antipsychotic used for schizophrenia and bipolar disorder. Both drugs have been known to reduce body temperature since the 1950s. Physical cooling methods such as blankets, ice packs, and helmets have been tested previously for post-stroke hypothermia.

The study is published in Science Translational Medicine with DOI 10.1126/scitranslmed.ady7847.