ALTERATIONS IN RESPONSE TO SOMATIC PAIN ASSOCIATED WITH ANAESTHESIA: XII: FURTHER STUDIES WITH ATROPINE

Abstract

SUMMARY The intramuscular injection of atropine 0.6 mg is followed by a slight, but significant, increase in sensitivity to somatic pain which can be detected 20 minutes after adminis-tration, but which has passed off within a further 20 minutes. It also decreases the analgesic action of pethidine and pethidine-phenothiazine mixtures in a similar time relationship. The incidence of excitatory phenomena following methohexitone 1.6 mg/kg is significantly increased if the time between the administration of the pre-operative dose of atropine and induction of anaesthesia is reduced from 60 to 20 minutes.