Imipramine and tinnitus.

Although tinnitus is listed among the rare neurologic side effects of tricyclic antidepressants, little is known about its prevalence, mechanism of development, course, and management. A chart review of 475 patients treated with tricyclic antidepressants indicated that tinnitus occurred in about 1% of the patients. The case vignettes of 5 patients who developed tinnitus in the course of imipramine therapy are presented. Each developed tinnitus in the second or third week of treatment with imipramine at daily dosages of 150-250 mg and at combined plasma imipramine-desipramine levels between 200-450 ng/ml. In each patient, tinnitus subsided spontaneously within 2-4 weeks of onset without any specific treatment, even though the daily dosage of imipramine and the plasma tricyclic levels were constant or increased. Possible mechanisms of development of tinnitus and implications for tricyclic antidepressant therapy are discussed.