Dexmedetomidine, diazepam, and propranolol in the treatment of ethanol withdrawal symptoms in the rat

In this study, the effects of dexmedetomidine, a selective alpha 2-adrenoceptor agonist, on ethanol withdrawal symptoms, were compared with those of diazepam and propranolol. The rats were given highly intoxicating doses of ethanol for 4 days. After the intoxication period, rats were divided into four equal groups: a dexmedetomidine-treated group (30 micrograms/kg, sc), a diazepam-treated group (2 mg/kg, sc), a propranolol-treated group (5 mg/kg, sc), and a control group with no medication. Medication was given in the withdrawal phase-2, 8, 14, and 20 hr after the onset of the withdrawal symptoms. The severity of the ethanol withdrawal symptoms (rigidity, tremor, irritability, and hypoactivity) was observed up to 33 hr after the onset of the ethanol withdrawal symptoms. Both dexmedetomidine and diazepam significantly relieved tremor compared with the control group. Diazepam reduced irritability significantly, compared with the control group. When measured as the sum score of the three most specific withdrawal signs (rigidity, tremor, and irritability), dexmedetomidine and diazepam significantly relieved the ethanol withdrawal reaction. Propranolol attenuated tremor, but was inefficient against other withdrawal symptoms. Dexmedetomidine may thus represent a new effective drug in the treatment of the ethanol withdrawal syndrome.