Comparison of growth hormone and prolactin stimulation induced by chlorimipramine and desimipramine in man in connection with chlorimipramine metabolism.

In order to compare the effects of chlorimipramine (CI) and desimipramine (DMI) on growth hormone (GH) and on prolactin (PRL) secretion equal doses of 25 mg CI or DMI were administered i.v. to 12 healthy subjects each. In this dose, DMI, which primarily inhibits norepinephrine (NE) uptake, induced a significantly higher GH stimulation, compared to CI, whereas CI, which primarily inhibits serotonin (5-HT) uptake induced a significantly higher PRL stimulation, compared to DMI. Following DMI administration, an increase in GH (greater than 7.5 ng/ml) was found in all subjects, after CI in only about 50% of the subjects. The varying interindividual GH secretions after CI are discussed on the basis of the different plasma levels of CI and of its metabolite desmethyl-chlorimipramine (DCI), which is a NE uptake-inhibitor.