Lithium accelerates the development of tolerance to alcohol in rats

Thirty male Wistar rats, trained on the moving belt test, were used to test the effect of acute and chronic lithium administration on tolerance to alcohol. Over the first 11 days, a group receiving lithium (1.5 mequiv./kg, i.p.) 4 h before and alcohol (2 g/kg, i.p.) 17 min before three daily 2-min test trials on the moving belt showed accelerated development of tolerance to alcohol compared with a group receiving saline (instead of lithium) and the same dose of alcohol. There were no differences between the groups in the level of tolerance finally reached and no differences could be detected in the effects of lithium on physiological as opposed to behaviorally augmented tolerance. Also, 12 days of lithium pretreatment did not increase tolerance to an initial dose of alcohol or modify the expected blood alcohol level. Conversely, tolerance, as a result of 12 days of chronic alcohol pretreatment, was not increased further by a single lithium administration. Drug-free performance at the end of the experiment showed that the injection procedure per se did not influence performance.