February 1977

Clinical Implications of Imipramine Plasma Levels for Depressive Illness

Author Affiliations

From the New York State Psychiatric Institute and the Departments of Psychiatry and Public Health, Columbia University, College of Physicians and Surgeons, New York.

Arch Gen Psychiatry. 1977;34(2):197-204. doi:10.1001/archpsyc.1977.01770140087010

• Sixty depressed nonschizophrenic patients were admitted to a research unit. Following one drug-free week and one week of placebo, patients received 3.5 mg/kg of imipramine hydrochloride for 28 days. Plasma levels of imipramine and its metabolite desipramine hydrochloride (desmethylimipramine) were measured three times weekly and the relationship between plasma steady-state levels and clinical outcome was examined. Steadystate levels ranged from 50 to 1,050 ng/ml. There was a statistically and clinically significant relationship between plasma levels and response. The relationship existed across the entire sample, and was accentuated when the bipolar and unipolar nondelusional populations were examined. Because a strong relationship between sex and outcome was observed, the unipolar nondelusional patients were stratified by sex and a significant relationship still persisted. Only the unipolar delusional patients failed to demonstrate an association between blood level and clinical response.

(Arch of Gen Psychiatry 34:197-204, 1977)