SSRIs and cardiotoxicity

Q: Which of the Selective Serotonin Reuptake Inhibitors (SSRIs) is the most cardiotoxic? (select one)

A) citalopram

B) escitalopram 

C) fluoxetine

D) paroxetine

E) sertraline 

Answer: A

The major cardiotoxicity from citalopram (and other SSRIs) is due to prolong QTc interval, ultimately leading to torsades de pointe. Citalopram is metabolized in the liver and produces desmethylcitalopram (DCT) and didesmethylcitalopram (DDCT). The latter is cardiotoxic.

Citalopram is five times more likely to prolong the QTc interval when compared to other SSRIs. It can also cause left and right bundle branch blocks, Premature ventricular beats (PVCs), sinus bradycardia or tachycardia, supraventricular tachycardia, ST segment changes, and in extreme cases ventricular fibrillation. It is also known to cause seizures.

Bicarbonate infusion can be a lifesaver.

#toxicology

#pharmacology

#psyvhiatry

References:

1. Personne M, Sjöberg G, Persson H. Citalopram overdose--review of cases treated in Swedish hospitals. J Toxicol Clin Toxicol 1997; 35:237.

2. Personne M, Persson H, Sjöberg E. Citalopram toxicity. Lancet 1997; 350:518.

3. Kelly CA, Dhaun N, Laing WJ, et al. Comparative toxicity of citalopram and the newer antidepressants after overdose. J Toxicol Clin Toxicol 2004; 42:67.