Major
citalopram × venlafaxine
SSRI (selective serotonin reuptake inhibitor)×SNRI (serotonin-norepinephrine reuptake inhibitor)
Mechanism
SSRI + SNRI – serotonin syndrome, additive QT prolongation at high venlafaxine doses.
Symptoms
Serotonin syndrome: agitation, confusion, tremor, myoclonus, hyperreflexia. Autonomic features: sweating, tachycardia, hypertension, fever. First signs appear within hours of co-administration.
Management
The combination is not prescribed. When switching antidepressants, allow a 1-week washout. For augmentation, use mirtazapine or agomelatine.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.