How safe are psychiatric medications after a voluntary overdose?

Abstract

Purpose: This study assessed psychiatric medications and their potential lethality in a representative sample of suicide attempts.

Materials and methods: During 1996-98, 563 suicide attempts were studied in a general hospital in Madrid (Spain). Medication overdose was used in 456 suicide attempts (81%). The ratio between dose taken and maximum prescription dose recommended was used to evaluate the medication toxicity.

Results: Benzodiazepines were the drugs most often used in self-poisoning (65% of overdoses), followed by new antidepressants (11%), tricyclic antidepressants (TCAs) (10%), and antipsychotics (8%). An overdose with any of the three latter psychiatric medications was significantly more frequent in patients prescribed those medications. The overdoses for TCA were potentially lethal in 47% of the cases. However, all patients who overdosed on psychiatric medications recovered well and were discharged without any sequelae.

Discussion: This study suggests that psychiatric medications, particularly benzodiazepines, new antidepressants and antipsychotics, are relatively safe when they are used for self-poisoning. If patients with mental illnesses are under treated, there is a clear and documented higher risk for suicide.

Conclusion: It is better to prescribe psychiatric medications, particularly the new ones, rather than withhold them due to an exaggerated fear of a lethal overdose