Tricyclic antidepressants: a review of their toxicology

The tricyclic antidepressants have a complex interaction with several tissues both in experimental animals and in man. Side effects exerted by these drugs may be so severe as to justify a careful management of each individual depressed patient. The clinician must be aware of these effects above all in treating overdose poisoning and suicide attempts. This paper reviews the tricyclic-induced organic and psychologic disturbances, attention being paid to the antidepressant pharmacodynamics and the importance of biogenic amines-reuptake inhibition. Further studies on the pharmacokinetics of tricyclic antidepressants are needed however to clarify the mechanisms of their side effects. In this situation, increased drug levels should be tried only after lower dosages have proved ineffective in relieving the depressive symptomatology. In any case, the greatest caution should be used in the treatment of patients with cardiovascular diseases, severe hypertension, glaucoma, or a tendency to retain urine. Nevertheless, at present no new antidepressant has been found which may offer more selective therapeutic advantages than the classical tricyclic thymoleptics (imipramine-like drugs).