Multiple administration of carbamazepine, typical and atypical antidepressant drugs on clonidine-induced hypoactivity...

The chronic effects of carbamazepine were compared with those of typical and atypical antidepressant drugs on clonidine--induced hypoactivity in mice. The results indicated that clonidine at a dose of 0.05-0.10-0.15 mg/kg i.p. produced a dose-dependent depressant effect on the exploratory behavior, as shown by the marked reduction in ambulation and rearing in an "open-field" test. Chronic pretreatment with imipramine 20 mg/kg i.p. and desipramine 5-10 mg/kg i.p. for 14 days resulted in a significant reduction in clonidine-induced hypoactivity. Repeated pretreatment with atypical antidepressant drugs (trazodone 5-10 mg/kg i.p.:, fluoxetine 5-10 mg/kg i.p., or rubidium chloride 24-48 mg/kg i.p.) as well as carbamazepine 10-20 mg/kg i.p., had no significant effect on clonidine-induced hypoactivity. In summary, these findings provide further evidence for a subsensitivity of presynaptic alpha 2-adrenoceptors in animals chronically treated with imipramine or desipramine and a behavioural profile of carbamazepine similar to that of atypical antidepressant drugs.