CriticalCentrally acting cough suppressant×Oxazolidinone antibiotic
Updated · Methodology
Mechanism
Linezolid is a reversible MAO inhibitor. Dextromethorphan is a weak serotonin reuptake inhibitor and sigma-1 agonist. The combination produces synaptic serotonin accumulation and serotonin syndrome.
Symptoms
Within hours of co-administration: agitation, confusion, tachycardia, hypertension, hyperthermia, tremor, myoclonus, hyperreflexia. Severe cases – seizures, coma, rhabdomyolysis.
Management
The AEMPS label for dextromethorphan lists linezolid among contraindicated combinations. Avoid dextromethorphan for the linezolid course (typically 7–14 days). Alternative antitussives: guaifenesin or honey for nocturnal cough. If dextromethorphan was already taken, stop linezolid; serotonin syndrome resolves within 24 hours.
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.
Summary of a multi-drug list →
Medicine list: everything you take in one place →
Sources
- FDA: Zyvox (linezolid) prescribing information (2018)– ; DailyMed setid 6e70e63b-bfd5-478d-a8ee-8ba22c9efabd
- AEMPS: Ficha técnica: Dextrometorfano (nº registro 70997), sección 4.3 (2026)– AEMPS, CIMA, nº registro 70997 (Laitos 3 mg/ml jarabe), revisión 08/2026, sección 4.3