Adverse event reporting with selective serotonin-reuptake inhibitors

OBJECTIVE: The Weber effect is a phenomenon which states that the number of reported adverse reactions for a drug increases until the middle to end of the second year of marketing. The purpose of this study was to examine the number of adverse event reports associated with specific selective serotonin-reuptake inhibitor (SSRI) use. METHODS: Data used in this study included voluntary adverse event reports submitted to the US federal government through the Spontaneous Reporting System and Adverse Event Reporting System. Adverse event reports were analyzed for the following SSRIs: citalopram, fluoxetine, fluvoxamine, paroxetine, and sertraline. RESULTS: Adverse event reporting associated with fluvoxamine demonstrates the Weber effect. Adverse events related to fluoxetine, paroxetine, and sertraline do not exhibit the Weber effect. Fluoxetine-related adverse events peaked at year 3, with peaks also occurring during the 10th and 12th years after market entry. Adverse event reports associated with paroxetine and sertraline use increased 5-8 years after market entry. CONCLUSIONS: Within 1 class of medications, it is possible for a few agents to exhibit the Weber effect, while there is no definite pattern with others. A new observation in adverse event reporting is introduced and suggests that a peak in adverse event reporting occurs 1-2 years after a medication receives approval for a new indication. Future research is necessary to validate this effect and examine the generalizability to other medications.