Effects of midazolam on pain sensations in the face

Objectives. This study investigated the effects of midazolam, a sedative, on tactile and pain sensations on the skin of the chin. Study Design. Thirty-seven volunteers were segregated into four groups; the first group was the control group; the second to fourth groups were administered 0.025 mg/kg, 0.05 mg/kg, and 0.075 mg/kg of midazolam, respectively, as a bolus injection. All volunteers reclined in a dental chair for the experiment. Tactile and pain sensations were determined over time after injection of midazolam, the former using von Fray thread, the latter using an esthesiometer. Results. Thresholds of tactile sensitivity and of pain were statistically significantly different from control values at 10 minutes after injection of midazolam in the 0.05 mg/kg group and in the 0.075 mg/kg group. Conclusion. Although 0.025 mg/kg of midazolam produced sedation, at least 0.05 mg/kg of this agent was required to alter the thresholds for perception of tactile and painful stimulation.