Respiratory effect of THIP, a GABA-agonistic analgesic, during halothane anaesthesia.

THIP, 4, 5, 6, 7-tetrahydroisoxazolo (5,4-) pyridin-3-ol, is a GABA-agonistic drug with analgesic effect, but apparently without respiratory depressant properties in awake subjects. The effect of THIP on the CO2 ventilation response was tested before, during and at the end of halothane anaesthesia in six male patients and compared to a control group. As there was no indication of respiratory depression by THIP, the drug may have a future in the treatment of postoperative pain if an analgesic effect is confirmed under clinical conditions.