THE SEROTONIN SYNDROME AND PSYCHOSIS-LIKE SIDE-EFFECTS OF FLUVOXAMINEIN CLINICAL USE - AN ESTIMATION OF INCIDENCE

Objective: The incidence of the serotonin syndrome or serotonin-syndro me-like side effects during treatment with the selective serotonin reu ptake inhibitor (SSRI) fluvoxamine should be evaluated. Method: 200 in patients treated for the first time with fluvoxamine were prospectivel y evaluated for the occurrence of a serotonin syndrome over a period o f 8200 treatment days. Retrospective follow-up data of outpatient trea tment covered 8891 days. Results: No full-blown serotonin syndrome occ urred, but 3 patients developed a reversible change of mental status w ith insomnia, agitation, confusion and incoherent thoughts without oth er symptoms of the serotonin syndrome. Conclusions: It is concluded th at the occurrence of a potentially lethal serotonin syndrome is rare i n fluvoxamine treatment, but psychosis-like syndromes as a side effect of serotonergic stimulation might occur. In the investigated sample t he rate was 0.006-0.04 per 100 treatment days. (C) 1997 Elsevier Scien ce B.V.