Psychiatric Side Effects of Tricyclic Antidepressants

Psychiatric toxicity to tnicycic antidepressants may be an underrecognized adverse effect of treatment with tricyclics, possibly occurring in between 5 and 15 percent of patients. Such toxicity is probably mediated by a central antimuscarinic action of the tricyclics and is associated with elevated plasma tricyclic levels, age, polypharmacy, and perhaps underlying cholinergic defects in susceptible individuals. Once tricyclic-induced toxicity is recognized, the treatment consists of discontinuing the tricyclic and providing supportive care as necessary. Many cases of tricyclic-induced toxicity may be preventable through close attention to the mental status examination and judicious monitoring of plasma tricyclic levels during treatment.