Reversal of cocaine withdrawal-induced anxiety by ondansetron, buspirone and propranolol.

Cocaine is used worldwide and considered a public health problem. Relapse from addiction is one of the difficulties faced by cocaine users, and in most cases according to the period of abstinence, users may present symptoms such as anxiety or depression. To evaluate the anxiety-like behavior induced by different periods, rats were treated for 7 days with cocaine 20 mg/kg, i.p., and 24 h, 7 and 21 days after drug withdrawal were submitted to the elevated plus maze (EPM) and the open field (OF) tests. In different protocol, propranolol (10 mg/kg, i.p.), ondansetron (4 mg/kg, i.p.) and buspirone (5 mg/kg, i.p.) were administered once after 24 h and 7 days of abstinence from cocaine to evaluate possible reversal or attenuation of the symptoms caused by cocaine withdrawal. EPM results showed a reduction in all parameters after 24 h and 7 days of the last exposure to cocaine, indicating anxiety-like behavior. In the OF test, 24 h and 7 days of abstinence showed increased locomotor activity, while in the withdrawal 21 days the animals not alter the locomotor activity. The administration of propranolol, ondansetron or buspirone after a 24 h abstinence period reduced the animalś anxiety in the EPM, and in the OF all drugs were able to reduce locomotor activity. After abstinence 7 d, the drugs reduced locomotor activity in the OF, in the EMP propranolol and ondansetron reversed the anxiogenic effect induced by cocaine. These results suggest that the treatment of anxyogenic effects of abstinence from cocaine is dependent on the period of the withdrawal.