Which antidepressant is considered effective but has a higher risk of toxicity?

Tricyclic antidepressants (TCAs) are indeed known to be effective in the treatment of depression but carry a higher risk of toxicity compared to other classes of antidepressants. This increased toxicity primarily arises from their mechanism of action and their pharmacological profile.

TCAs affect multiple neurotransmitter systems by blocking the reuptake of norepinephrine and serotonin, but they also antagonize various receptors, including muscarinic acetylcholine receptors, histamine receptors, and alpha-1 adrenergic receptors. This broad spectrum of activity can lead to a range of side effects, including cardiotoxicity, particularly in overdose situations, where they can cause arrhythmias, prolonged QT interval, and even cardiac arrest.

Moreover, the potential for toxicity in TCA overdose is significantly higher than that of SSRIs, SNRIs, or MAOIs, making them more dangerous in terms of poisoning risk. While MAOIs are also associated with certain dietary restrictions and can lead to hypertensive crises if tyramine-rich foods are consumed, their overall acute toxicity profile in overdose situations does not surpass that of TCAs.

Therefore, the efficacy of TCAs in treating depression is coupled with a notable risk for toxic effects, especially in cases of overdose, which