WITHDRAWAL REACTIONS WITH SELECTIVE SEROTONIN REUPTAKE INHIBITORS AS REPORTED TO THE WHO SYSTEM

Objective: The present study was performed both to investigate whether there might be a difference between the selective serotonin re-uptake inhibitors, (SSRIs) with regard to the incidence of withdrawal reacti ons, and to describe the associated symptoms. From the WHO database, t herefore, all case reports from the year of introduction for each of t he SSRIs, fluoxetine, paroxetine and sertraline, were retrieved. Sales figures were obtained from Intercontinental Medical Statistics Intern ational. The reporting rates were calculated as the number of reports per million defined daily doses (DDDs) sold per year. Results: The rep orting rate of withdrawal reactions for paroxetine was found to be hig her than that for sertraline and fluoxetine in each of the countries s elected for detailed analyses (US, UK and Australia), as well as for a ll 16 countries combined. Moreover, using the WHO system of organ clas sification, the ratio of central nervous system to psychiatric withdra wal symptoms was 1.9 and 2.1 for paroxetine and sertraline, respective ly, whereas that for fluoxetine was 0.48, indicating a possible qualit ative difference between the SSRIs with respect to the nature of the w ithdrawal syndrome.