Adverse event reporting with selective serotonin-reuptake inhibitors

Area of Science:

• Pharmacovigilance
• Drug safety monitoring
• Clinical pharmacology

Background:

• The Weber effect describes an initial rise in reported adverse drug reactions (ADRs) peaking in the second year of a drug's market presence.
• Understanding ADR reporting patterns is crucial for post-market drug surveillance.

Purpose of the Study:

• To investigate the presence of the Weber effect in the reporting of adverse events for specific selective serotonin-reuptake inhibitors (SSRIs).

Main Methods:

• Analysis of voluntary adverse event reports submitted to US federal systems (Spontaneous Reporting System, Adverse Event Reporting System).
• Evaluation of SSRIs including citalopram, fluoxetine, fluvoxamine, paroxetine, and sertraline.

Main Results:

• Fluvoxamine exhibited the Weber effect, with increased adverse event reports in the early post-marketing period.
• Fluoxetine, paroxetine, and sertraline did not consistently demonstrate the Weber effect, showing later peaks or varied patterns.
• Fluoxetine ADRs peaked at year 3 and later (10th, 12th years); paroxetine and sertraline showed increases 5-8 years post-market.

Conclusions:

• Adverse event reporting patterns, including the Weber effect, can vary significantly even within the same drug class (SSRIs).
• A novel observation suggests a potential peak in adverse event reporting 1-2 years after a drug gains approval for a new indication.
• Further research is needed to confirm this new observation and assess its applicability to other medications.