Moderate
Linezolid × Morphine
Oxazolidinone antibiotic×Natural opium alkaloids
Mechanism
Linezolid is a reversible MAO inhibitor and may mildly potentiate opioid CNS depression. Morphine does not cause serotonin syndrome directly (minimal serotonergic effect).
Symptoms
Sedation, fatigue, slowed reactions, impaired coordination. In older patients: fall and fracture risk. Driving and operating machinery: accident risk. Possible sedation increase and respiratory rate decrease.
Management
On the combination, do not raise morphine until linezolid ends (10–14 days). On a stable maintenance morphine dose (chronic pain, palliative care), adjustment is usually not needed. If marked sedation or bradypnoea develops, reduce morphine by 25%. Alternatives if available: fentanyl or hydromorphone (no serotonergic risk).
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.