Characterization of the Adverse Effects Induced by Acetaminophen and Nonsteroidal Anti-Inflammatory Drugs Based on the Analysis of the Japanese Adverse Drug Event Report Database.

OBJECTIVES: Acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) are antipyretic analgesics with established adverse effects (AEs); however, only a few studies have compared their AEs simultaneously. We aimed to compare the AEs of these medications to confirm the respective frequencies of both rare and major AEs.

METHODS: We used a high-quality database for spontaneous adverse drug event reporting in Japan. Data were extracted regarding the AEs of acetaminophen and NSAIDs to compare the tendency of the appearance of those AEs between the drugs. We also performed a principal component analysis using the AE data to assess the characteristics of major AEs.

RESULTS: Cutaneous disorders and hepatic disorders were the most common AEs induced by acetaminophen and NSAIDs, with gastrointestinal tract disorders also common with NSAID use. Principal component analysis quantitatively showed the tendencies of specific AEs, and it helped demonstrate the characteristics of AEs. Acetaminophen and NSAIDs showed different tendencies in the occurrence of AEs. Each NSAID was plotted based on the tendency of the appearance of major AEs, and AEs were classified by their likelihood of being pharmacological or idiosyncratic.

CONCLUSIONS: These findings may help clinicians select an appropriate drug for patients considering their backgrounds, instead of choosing merely based on the class of the drug, for example, cyclooxygenase selectivity. This selection, based on the characteristic information on AEs occurring in clinical settings, might be more suitable for patients.