Tricyclic antidepressant overdose: clinical and pharmacologic observations

Forty-seven patients with confirmed TCA overdoses were thoroughly evaluated with regard to clinical and electrocardiographic findings. In 22 patients plasma levels of the primary TCA and the desmethyl metabolite were determined. We found that both neurologic and cardiovascular complications were common, but independent of each other. While plasma levels of the parent of TCA compound correlated best with the neurologic disturbances, cardiac abnormalities were more related to the desmethyl metabolite level. Although plasma levels correlate with the clinical findings, sufficient overlap between normal and abnormal levels and findings exist that we do not feel that routine measurement of plasma levels is clinically useful at this time.