Tricyclic Antidepressants (TCAs) 2nd line treatment for depression Inhibit reuptake of ______, ________________________ . Antagonize 3 A's __,,. Work as sodium and calcium channel inhibitors as well. Therapeutic index of 7 meaning taking 7 times the normal amount of the drug could cause death. How much do you give in each prescription? What do you get and give with an overdose?