Diazepam does not prevent succinylcholine-induced fasciculations and myalgia. A comparative evaluation of the effect of diazepam and d-tubocurarine pretreatments.

To determine the effectiveness of diazepam pretreatment in preventing succinylcholine (SCh)-induced fasciculations and body pains, 587 patients were randomly allocated to six groups. Patients in Group I received no pretreatment and served as controls. Patients in Groups II and III were pretreated with 0.05 mg/kg of diazepam either 4-5 min (Group II) or 8-10 min (Group III) prior to SCh administration. Patients in Groups IV and V received 0.1 mg/kg of diazepam either 4-5 min (Group IV) or 8-10 min (Group V) prior to SCh administration, while patients in Group VI were pretreated with 0.05 mg/kg of d-tubocurarine (dTc) 4-5 min prior to SCh. The succinylcholine dosage was 1.0 mg/kg in Groups I through V and 1.5 mg/kg in Group VI. Fasciculations, intubation conditions and postoperative body pains were evaluated in all groups. Fasciculations were seen in 90% of patients in the control group and 15% in the dTc pretreatment group, while diazepam was ineffective in altering the frequency or intensity of fasciculations. Conditions for intubation were judged to be clinically adequate in all groups. Body pains were seen in 33% of patients in the control group and 28-36% in diazepam-pretreated groups and in only 8% of patients in the dTc pretreatment group. There was no statistically significant difference in the incidence of body pains by virtue of site of operation, age, sex, and inpatient/outpatient status. It is concluded that the problem of postoperative myalgia is significant and that dTc pretreatment is the effective method for prevention of fasciculations and postoperative myalgia. Diazepam pretreatment was ineffective for the prevention of fasciculations and myalgia.