Serotonergic antidepressants and linezolid: a retrospective chart review and presentation of cases

To report the results from a retrospective chart review looking at the combination of linezolid and serotonergic antidepressants and to report two cases of serotonin syndrome which were identified at our hospital.

During the retrospective chart review one case of serotonin syndrome was identified. A 65-year-old female was receiving escitalopram for the treatment of depression prior to admission. Linezolid therapy was initiated on admission and two days later the patient had a tonic-clonic seizure. Escitalopram was discontinued and the patient did not have any further seizure activity. In a second case, a 37-year-old male was receiving citalopram during hospitalization and was started on concomitant linezolid. The patient had myoclonus and was observed to be tremulous throughout therapy with linezolid. Ten days after discontinuation of linezolid the patient continued to have symptoms until the withdrawal of citalopram. The Naranjo probability scale scores the first case as possibly related and the second case as probably related to the combination.

It has been well documented in the literature that the combination of linezolid and serotonergic antidepressants may cause serotonin syndrome. In this retrospective chart review only one patient of 53 (1.8%) had symptoms highly suggestive of serotonin syndrome. A second patient continued to have symptoms of serotonin syndrome even after withdrawal of linezolid.

This retrospective review and subsequent case reports confirm the rare, but serious, potential of serotonin syndrome associated with the combination of linezolid and serotonergic antidepressants.