Drug-associated tongue discoloration: a comprehensive assessment of USFDA adverse event reporting system using disproportionality analysis

BACKGROUND: Drug-induced tongue discoloration can impact quality of life but remain under-recognized. While several antimicrobials are implicated, comprehensive signals across many drug classes remain poorly characterized. METHODS: Reports of tongue discoloration, strawberry tongue, and black hairy tongue were extracted from the USFDA Adverse Event Reporting System from 2004 to 2024. Disproportionality analysis was conducted using reporting odds ratio, proportional reporting ratio, Bayesian confidence propagation neural network, and multi-item gamma Poisson shrinker to detect associations between implicated drugs and tongue conditions. RESULTS: A total of 2352 reports were analyzed. Drugs consistently associated with tongue discoloration by both frequentist and Bayesian analyses included clarithromycin, metronidazole, linezolid, amoxicillin, and fluticasone. Flucloxacillin and immunoglobulin G emerged as risks for strawberry tongue. Meclizine showed a signal for black hairy tongue across methods, whereas other drugs appeared risk factors using only frequentist tests. Demographic patterns varied by condition. CONCLUSION: This comprehensive signal detection revealed several high-priority drug-tongue condition associations using large-scale pharmacovigilance data. Findings carry implications for guiding clinical practice through enhancing adverse effect monitoring for high-risk medications. Priority signals merit validation through further research to optimize benefit-risk assessment and reduce preventable tongue disorders.