Critical
Fluoxetine × Linezolid
Selective serotonin reuptake inhibitors×Oxazolidinone antibiotic
Mechanism
Fluoxetine (SSRI) raises synaptic serotonin. Linezolid reversibly inhibits MAO. The pair is notable because fluoxetine's active metabolite, norfluoxetine, persists for up to 5 weeks – the serotonergic effect outlasts dosing.
Symptoms
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.
Management
The combination is not prescribed. Stop fluoxetine at least 5 weeks before planned linezolid. For acute antibiotic need, use vancomycin or daptomycin. If linezolid is still required, monitor for serotonin syndrome during therapy plus 5 weeks after fluoxetine discontinuation.
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.