Major
Sertraline × venlafaxine
Selective serotonin reuptake inhibitors (SSRIs)×SNRI (serotonin-norepinephrine reuptake inhibitor)
Mechanism
SSRI (sertraline) + SNRI (venlafaxine) – additive serotonergic load. The combination is not used in clinical practice.
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, add mirtazapine or agomelatine (different class).