The Value of Sensitivity Analyses in Assessing the Risk of Two Rare Neurological Adverse Events and Pseudoephedrine Use

Determining the risk of rare adverse events (AEs) related to prescription medicines is challenging, and this challenge is further compounded when considering risks of nonprescription medicines. Nonprescription medicines are frequently used without direct clinical supervision, and active surveillance systems for potential adverse drug events are generally focused on pre-specified outcomes and prescription medicines. Additionally, when AEs are assessed using passive surveillance systems, such systems often lack measurement of drug exposure, unexposed controls for comparison, and comprehensive information to control for factors that could confound causality and influence the frequency and severity of AEs.