Major
Mirtazapine × Sertraline
Other antidepressants (NaSSA)×Selective serotonin reuptake inhibitors (SSRIs)
Mechanism
SSRI augmentation with mirtazapine in resistant depression is possible ('California rocket fuel'). Additive serotonergic effect is rare, but serotonin syndrome has been reported at high doses of both.
Symptoms
Serotonin syndrome: agitation, confusion, tremor, myoclonus, hyperreflexia. Autonomic features: sweating, tachycardia, fever.
Management
The combination is used for antidepressant augmentation. Keep doses low: sertraline 100 mg, mirtazapine 30 mg/day. Monitor blood pressure and mental status in the early weeks.