Alterations in response to somatic pain associated with anaesthesia. III. The effect of hydroxydione.

IN a previous publication, the author reported that an increased sensitivity to pain followed the use of small doses of thiopentone and pentobarbitone (Dundee, 1960), thus confirming the findings of Clutton-Brock (1960). It was suggested that this anti-analgesic action of thiopentone was due to low concentrations of the drug in the brain and the phenomenon was also demonstrated in the postoperative period following moderate and large doses of the drug. On occasions it persisted for as long as five hours after injection of the thiopentone. Clutton-Brock (1960) has also stated that the anti-analgesic action of the barbiturates is not shared by hydroxydione. This brief communication reports and discusses data which substantiate his findings.