Investigation of the orthostatic reaction after intravenous administration of imipramine, chlorimipramine, and imipramine-N-oxide

Abstract

Three age- and sex-matched groups of 10 patients were treated i.v. with imipramine, chlorimipramine and imipramine-N-oxide, respectively, in increasing doses from 25 mg to 150-175 mg given as single daily infusions during 1 h. No systemic changes of heart frequency and blood pressure were found during the infusions despite the high dosage of tricyclic antidepressants given in such a short period as 1 h. The patients were examined regarding orthostatic reactions as well as ECG changes before, after 4-5 infusions and after 8-10 infusions. There were more orthostatic abnormalities and ECG changes in the patients treated with imipramine than in those treated with imipramine-N-oxide and there were practically no changes in the chlorimipramine group. No statistically significant orthostatic changes were found.