Can you take Zoloft and citalopram together?

NEVER!Coadministration with fluoxetine may significantly increase the plasma concentrations of some tricyclic antidepressants (TCAs) especially nortriptyline.

The combination of fluoxetine (or any other selective serotonin reuptake inhibitor) and a TCA such as nortriptyline may potentiate the risk of serotonin syndrome, which is a rare but serious and potentially fatal condition thought to result from hyperstimulation of brainstem 5HT1A receptors.

BTW, I once had serotonin syndrome; it was no picnic! I nearly died.