Preclinical evaluation of riluzole: assessments of ethanol self-administration and ethanol withdrawal symptoms.
BACKGROUND
Many of the neurobehavioral effects of ethanol are mediated by inhibition of excitatory N-methyl-D-aspartate (NMDA) and enhancement of inhibitory gamma-amino-butyric-acid (GABA) receptor systems. There is growing interest in drugs that alter these systems as potential medications for problems associated with alcoholism. The drug riluzole, approved for treatment of amyotrophic lateral sclerosis (ALS), inhibits NMDA and enhances GABA(A) receptor system activity. This study was designed to determine the preclinical efficacy of riluzole to modulate ethanol self-administration and withdrawal.


METHODS
Male C57BL/6J mice were trained to lever press on a concurrent fixed-ratio 1 schedule of ethanol (10% v/v) versus water reinforcement during daily 16-hour sessions. Riluzole (1 to 40 mg/kg, IP) was evaluated on ethanol self-administration after acute and chronic (2 week) treatment. To determine if riluzole influences ethanol withdrawal-associated seizures, mice were fed an ethanol-containing or control liquid diet for 18 days. The effects of a single injection of riluzole (30 mg/kg) were examined on handling-induced convulsions after ethanol withdrawal.


RESULTS
Acute riluzole (30 and 40 mg/kg) reduced ethanol self-administration during the first 4 hours of the session, which corresponds to the known pharmacokinetics of this drug. Ethanol self-administration was also reduced by riluzole after chronic treatment. Riluzole (30 mg/kg) significantly decreased the severity of ethanol-induced convulsions 2 hours after ethanol withdrawal.


CONCLUSIONS
These results demonstrate that riluzole decreases ethanol self-administration and may reduce ethanol withdrawal severity in mice. Thus, riluzole may have utility in the treatment of problems associated with alcoholism.
Department of Psychiatry, Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7178, USA.
Joyce
J
Besheer
Veronique
V
Lepoutre
Clyde W
CW
Hodge
D000428:Alcohol Drinking / Q000503:physiopathology / Q000517:prevention & control*; D020270:Alcohol Withdrawal Seizures / Q000503:physiopathology / Q000517:prevention & control*; D000818:Animals; D000927:Anticonvulsants / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical / Q000379:methods; D000431:Ethanol / Q000008:administration & dosage*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D012055:Reinforcement Schedule; D019782:Riluzole / Q000627:therapeutic use*; D012646:Self Administration
D000927:Anticonvulsants; D000431:Ethanol; D019782:Riluzole