Chilling the body with drugs could limit brain damage from stroke
New Scientist 2026-06-17 19:00:21
Context: Researchers have been investigating ways to limit brain damage caused by strokes, and a new approach involves using a combination of two drugs, promethazine and chlorpromazine, to cool down the body. This method has shown promise in reducing brain damage in mice and monkeys, and preliminary testing in humans has begun. The goal is to mitigate the effects of stroke by inducing a hibernation-like state in brain cells, reducing their need for oxygen and glucose.
Key Facts
- A combination of promethazine and chlorpromazine, used to treat hay fever and psychosis, was administered to mice and rhesus monkeys following induced strokes, resulting in reduced core body temperature, suppressed glucose metabolism, and lessened brain damage.
- The reduced brain damage in treated monkeys also meant they displayed better use of their limbs, suggesting a potential for improved motor function in humans.
- In a preliminary clinical trial involving 32 people who had just had a stroke, the promethazine and chlorpromazine treatment reduced patients' body temperature by 0.3°C, but did not significantly reduce stroke damage, likely due to the slow infusion rate over 12 hours.
- The researchers are now launching another trial to test faster infusions of the drugs over an hour, which may produce stronger cooling effects and therapeutic benefits.
- Promethazine and chlorpromazine are known to be relatively safe, having been used for decades to treat hay fever, sleep disorders, schizophrenia, and bipolar disorder, and act on the central nervous system to reduce core body temperature without causing shivering or subjective feelings of coldness.