Major
duloxetine × Linezolid
SNRI×Oxazolidinone antibiotic
Mechanism
Linezolid is a reversible monoamine oxidase (MAO) inhibitor. Duloxetine (SNRI) raises synaptic serotonin and norepinephrine. Co-administration: serotonin syndrome (FDA safety alert 2011, fatal cases reported).
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. Stop duloxetine at least 5 days before starting linezolid. For urgent antibiotic therapy: vancomycin, daptomycin, or ceftaroline by susceptibility.