ABSTRACT
In this study the effect of two benzodiazepines, diazepam and midazolam on postoperative succinylcholine myalgia was evaluated. The study included three equal groups of patients. Each group included 20 patients. The first group was taken as a control group. In the second group 0.15 mg/kg diazepam was injected i.v. 3 minutes before induction of anesthesia. In the third group 0.1 mg/kg midazolam was injected i.v. 3 minutes before induction of anesthesia. In the third group O.1 mg/kg midazolam was injected i.v. 3 minutes before induction of anesthesia. Both diazepam and midazolam reduced significantly succinylcholine induced myalgia. The incidence of succinylcholine myalgia in the diazepam group was 10% and in the midazolam group 15%, while in control group it was 55%. By application of the Chi-square test, there was a significant difference between the group given diazepam and the control group [Chi-square = 9.2, p <0.01]. The midazolam group also showed a significant difference when compared with the control group [Chi-square = 7, p <0.01]. When comparing diazepam group with midazolam group, no significant difference can be found between both groups. Concerning muscle fasciculations, diazepam reduced the incidence of fasciculations to 65% and midazolam to 60% in comparison with the control group which was 95%. Both benzodiazepines showed a significant reduction in the incidence of muscle fasciculations in comparison with the control group, where the Chi- square test revealed p <0.05 for diazepam and p <0.01 for midazolam, but no significant difference was found between the diazepam and midazolam groups. There was no correlation between the incidence of fasciculations and muscle pains. It is concluded that benzodiazepines have a prophylactic effect against succinylcholine muscle pains [myalgia]