ASYMPTOMATIC TRICYCLIC TOXICITY ASSOCIATED WITH DILTIAZEM

Therapeutic drug monitoring of tricyclic antidepressants is a controve rsial issue, A case is reported in which a patient with recurrent depr ession developed asymptomatic tricyclic toxicity while on trimipramine , a tricyclic antidepressant, and diltiazem, a calcium channel blocker A metabolic interaction involving cytochrome P450 3A (CYP3A) is postu lated. It is suggested that routine therapeutic drug monitoring of tri cyclic levels should be an essential part of the management of depress ion.