Relative toxicity of cyclic antidepressants.

Area of Science:

• Pharmacology
• Toxicology
• Clinical Medicine

Background:

• Cyclic antidepressants, including tricyclic antidepressants (TCAs), amoxapine, maprotiline, and trazodone, are commonly prescribed.
• Concerns exist regarding the central nervous system (CNS) and cardiac toxicity profiles of newer cyclic antidepressants compared to older TCAs.

Purpose of the Study:

• To compare the relative CNS and cardiac toxicity of amoxapine, maprotiline, and trazodone against older TCAs.
• To evaluate seizure incidence and cardiotoxicity in cyclic antidepressant overdoses.

Main Methods:

• A retrospective review of 1,313 cases of cyclic antidepressant exposures.
• Data collected from the Maryland Poison Center between 1981 and 1983.
• Comparison of seizure incidence and CNS depression across different antidepressant groups.

Main Results:

• Seizures were significantly more common in amoxapine (24.5%) and maprotiline (12.2%) overdose cases compared to TCAs (3.0%) and trazodone (0%).
• Desipramine ingestions also showed a higher seizure incidence (17.9%) versus other TCAs.
• No significant differences in CNS depression or cardiotoxicity were observed between the groups.

Conclusions:

• Findings support an increased risk of seizures with amoxapine and maprotiline overdoses.
• The study does not substantiate claims of reduced cardiotoxicity for amoxapine and maprotiline.
• Clinical vigilance for seizure risk is warranted in amoxapine and maprotiline overdoses.