The interaction between alpha-methyl-dopa and tricyclic antidepressants.

The central hypotensive action of alpha-methyl-DOPA is antagonized by tricyclic antidepressants like desipramine and imipramine. This antagonism has been demostrated in chloralose-anaesthetized cats. The drugs to be tested were infused into the left vertebral artery. The antagonism pProbably takes place in the pons-medulla region of the CNS. Probably, the alpha-adrenolytic properties of the tricyclic antidepressants bring about the blockade of central alpha-adrenergic receptors that are stimulated by alpha-methyl-noradrenaline, the biotransformation product of alpha-methyl-DOPA.