Effect of intramuscular diazepam infusion on herpes zoster-related pain in older patients: a randomized, double-blind, placebo-controlled trial

Abstract Objectives This study evaluated the effectiveness, psychological effects, and sleep quality using intramuscular diazepam infusion compared with placebo in patients with herpes zoster (HZ)-related pain. Methods The patients were randomized to either the diazepam or control group. The diazepam group received an intramuscular injection of diazepam for 3 consecutive days, while the control group received an intramuscular injection of 0.9% normal saline. The primary outcome was pain relief on posttreatment day 4, as measured using the Visual Analog Scale (VAS). Moreover, anxiety and depression were evaluated using the Generalized Anxiety Disorder-7 (GAD7) and Patient Health Questionnaire-9 (PHQ9), respectively. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). Results In total, 78 patients were enrolled in the trial. The mean differences in VAS scores between the two groups were 0.62 (P = 0.049) on posttreatment day 3 and 0.66 (P = 0.037) on posttreatment day 4. The effective rates of pain management in the diazepam group ranged from 10.26 to 66.67%, which were higher than those in the control group on posttreatment days 3 and 4 (P