The analgesic action of dexmedetomidine — a novel α2-adrenoceptor agonist — in healthy volunteers

Abstract

The analgesic efficacy of dexmedetomidine (DEX)--a novel alpha 2-adrenoceptor agonist--was studied in man. Single intravenous doses of fentanyl (FEN; 2 micrograms/kg), DEX (0.25, 0.50 and 1.0 micrograms/kg) and placebo were administered to 5 healthy male volunteers in a double-blind, crossover study in randomized order. The analgesic effect of the different treatments was measured by determining the time course of pain threshold with dental dolorimetry and by quantitating subjective pain induced by a standard ischemic pain stimulus on the upper arm using a visual analogue scale (VAS). The drugs were generally well tolerated. FEN and DEX both had analgesic effects on ischemic pain, which was seen as a statistically significant decrease in subjective VAS ratings. FEN appeared to be more effective than DEX; the difference was not, however, statistically significant. Neither of the drugs affected the pain threshold measurements.

Role of Intravenous Dexmedetomidine in Prolonging Postoperative Analgesia and Quality of Block Following Spinal Anaesthesia. A Systemic Review and Update

“…which was more longer in intrathecal route. There was no effect on the block onset or maximum block height [41].…”

“…The mechanism of synergistic action of dexmedetomidine on spinal local anaesthesia is still not clear. However, supra-spinal, spinal or direct analgesia and or vasoconstriction activities are involved [32,[37][38][39][40][41][42][43]. More-over, dexmedetomidine produces a greater degree of differential blockade by preferentially blocking the myelinated A alpha-fibers involved in motor conduction [27].…”

“…Few studies have evaluated the onset time of sensory block after spinal anaesthesia, Readdy et al have compared intravenous dexmedetomidine with clonidine reported that dexmedetomidine shortened onset of sensory-motor block [41] but other studies are not supporting the faster onset of sensory/motor block [12,13,[27][28][29][30]. Few study have reported intravenous dexmedetomidine shortened the onset time by 30-60 sec, which might be clinically significant but it was insignificant statistically [11,33,35].…”

Comparison of the Effects of Dexmedetomidine vs. Ketamine in Cardiac Ischemia/Reperfusion Injury in Rats – Preliminary Study

“…Dexmedetomidine supresses central adrenergic hormone secretion, and thus reduces the levels of plasma catecholamines causing the suppression of cardiac stimulant effects during the stress response in the surgery. Dexmedetomidine is also shown to have strong anesthetic and analgesic effects [16,17].…”

Intranasal Dexmedetomidine in Termination of First Trimester Pregnancy of Suction Evacuation

“…Intravenous infusion of dexmedetomidine is commonly used, but rapid administration or bolus might cause bradycardia and hypotension [14]. In addition, the analgesic effect of intravenous dexmedetomidine is inconsistent [15][16][17][18]. Therefore, different routes of administration and multimodal analgesia are suggested in future studies.…”