Reactions 481 - 11 Dec 1993

SMoclobemide + citalopram/clomipramine overdose

Fatal serotonin syndrome: 5 case reportsFive patients died of serotonin syndrome within 16 hours of

ingesting a mixed overdose of moclobemide with citalopramor clomipramine.

The first 2 patients, a 23-year-old man and a 19-year-oldwoman ingested moclobemide 1–1.5g and clomipramine225–500mg to "get high". Within 4–5 hours they developedextreme tremor, followed by seizures and loss ofconsciousness [treatment not indicated]. Both patients died9–10 hours after ingesting the 2 antidepressants. Blood levelsof the 2 agents on admission indicated only a moderateoverdose.

The other 3 patients, all men aged 26, 34 and 41 years,ingested an overdose of moclobemide and citalopram [dosesnot given]. They followed a similar pattern of events as theprevious 2 patients [treatment not indicated] and died within3–16 hours after the overdose. Blood levels of moclobemidewere 20–50 times higher than therapeutic levels in 2 patients;in one of these patients the citalopram level was also 5 timeshigher than the therapeutic level.

Author comment: ‘Our cases show that moclobemide,though a reversible and selective inhibitor of MAO-A[monoamine oxidase A], can rapidly cause a fatal serotoninsyndrome when ingested in mixed overdoses withserotoninergic drugs. Since death may follow within a fewhours of ingestion, treatment should be aggressive. One case ofnon-fatal serotonin syndrome has been described aftertherapeutic doses when the patient was switched fromclomipramine (50 mg daily) to moclobemide (300 mg daily).’Neuvonen PJ, et al. Five fatal cases of serotonin syndrome after moclobemide-citalopram or moclobemide-clomipramine overdoses. Lancet 342: 1419, 4 Dec1993 - Finland 800237767

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Reactions 11 Dec 1993 No. 4810114-9954/10/0481-0001/$14.95 Adis © 2010 Springer International Publishing AG. All rights reserved