Linezolid × Mirtazapine

Mirtazapine increases serotonin release by blocking presynaptic α2-adrenergic autoreceptors. Linezolid reversibly inhibits MAO. Combined action multiplies serotonergic activity.

Serotonin syndrome: agitation, confusion, tremor, myoclonus, hyperreflexia, dilated pupils. Autonomic features: profuse sweating, tachycardia, hypertension, fever above 38.5 °C. Severe cases progress to seizures, rhabdomyolysis, disseminated intravascular coagulation, and death. First signs appear within hours of concurrent dosing.

The combination is not prescribed. Stop mirtazapine at least 2 weeks before linezolid. As bridging therapy during antibiotic course, low-dose trazodone may be used cautiously for sleep. Alternative antibiotics: vancomycin, daptomycin.