Prevalence of Pruritus with Use of Metformin and Other Oral Hypoglycemic Agents

Abstract

Introduction: Metformin is being prescribed with increasing frequency for many dermatologic indications.1 This has resulted in anecdotal evidence correlating metformin use with pruritus, but the evidence is limited to case reports. 2,3 We aimed to investigate the association between metformin use and pruritus. Methods: Using the FDA Adverse Event Reporting System (FAERS), we performed a retrospective review of patients taking metformin, canagliflozin, insulin lispro, and insulin glargine between January 1, 2012, and November 14, 2022. Data was analyzed using Chi square and Fisher’s exact testing, with Bonferroni adjusted column proportions. Results: Prevalence of pruritus for patients taking metformin was 0.7%, canagliflozin 0.9%, insulin lispro 0.4%, and insulin glargine 0.6%. Canagliflozin was significantly more likely to cause pruritus than both insulin lispro and glargine (p-value<0.05). Reports of pruritus by metformin users was not significantly different than the other three oral hypoglycemics (p-value>0.05). Conclusion: Our results suggest that metformin is not significantly associated with pruritus and may be used for treatment of dermatologic conditions with little concern for this adverse event. Canagliflozin, however, was significantly likely to cause pruritus. General practitioners should consider counseling canagliflozin users on this significant adverse event.