Comparison of I.M. pethidine, diazepam and flunitrazepam as premedicants in children undergoing otolaryngological surgery.

Pethidine 1 mg kg-1, diazepam 0.25 mg kg-1 and flunitrazepam 0.02 mg kg-1 i.m. wer compared as premedicants in a double-blind study in 145 children undergoing otolaryngological surgery. Both flunitrazepam and pethidine had an anxiolytic effect in the children of less than 5 yr whereas diazepam had little effect. All of the drugs were anxiolytic in the children aged 5 yr and older. Sleep following thiopentone was restless more often in the younger than in the older children. Cardiovascular responses to thiopentone and to tracheal intubation were most obvious following benzodiazepines in children of less than 5 yr. After anaesthesia 10--33% of the older children could not recall pictures shown to them before anaesthesia. Forty-five (+/-SD 13) min after injection, the concentration of diazepam in serum was similar in both age groups; after 90 min it decreased in the younger and increased in the older children. All concentrations of flunitrazepam were significantly greater in the older compared with the younger children.