Action of antidepressant neuroleptics, chlorprothixene and levomepromazine, on the central noradrenergic system: comparison with other antidepressants.

In contrast to imipramine, chlorprothixene (CPX) and levomepromazine (LMZ) given chronically did not affect clonidine-induced hypothermia and depression of noradrenaline synthesis rate, while similarly to imipramine and citalopram depressed the density of cortical 3H-clonidine binding sites and increased their affinity. Two week treatment with the antidepressants did not affect the parameters of 3H-dihydroalprenolol binding sites, while spiroperidol administration increased their density, without changing KD values. The data suggest that changes in alpha 2 adrenoceptor population parameters may be a general characteristics of antidepressant treatment, but not necessarily followed by changes in clonidine effects.