escitalopram and linezolid

Pharmacodynamic interaction. Linezolid is a reversible, non-selective monoamine oxidase inhibitor (MAOI) that reduces the metabolism of serotonin. Escitalopram is a selective serotonin reuptake inhibitor (SSRI) that increases synaptic serotonin. Together they produce an excessive serotonergic state, leading to serotonin syndrome.

Co-administration can precipitate serotonin syndrome, a potentially fatal condition characterised by agitation, confusion, hyperthermia, autonomic instability, myoclonus, hyperreflexia and possibly cardiovascular collapse. Cases of serotonin syndrome with linezolid and SSRIs, including escitalopram, have been reported. The risk appears greatest when the drugs are given together, but delayed presentations can also occur.

Concomitant use is contraindicated. If linezolid is essential, discontinue escitalopram at least 5 half-lives (approximately 1 week) before starting linezolid. After stopping linezolid, wait at least 1 week (or the product label's advised interval) before resuming escitalopram. Monitor for symptoms of serotonin syndrome if the interaction is unavoidable. Consider alternative antibiotics or alternative antidepressants with no serotonergic activity.

Well-established. This interaction is documented in the prescribing information for both drugs and is listed as a contraindication in major drug interaction databases. Numerous case reports support the risk of serotonin syndrome.