Possible metformin-induced otorrhoea: A rare case

Background: Ear problems attributed to metformin use are not documented in the literature. Aim: To report a possible case of otorrhoea from metformin therapy. Clinical details: A 50-year-old male developed right ear discharge during metformin therapy. Outcomes: His ear discharge reappeared when metformin was reintroduced and disappeared when it was discontinued, suggesting a possible association between metformin and otorrhoea. The causality assessment revealed a 'probable' (Naranjo algorithm score 8) association and the severity was 'moderate' (Level 3). Conclusion: First case of possible otorrhoea from metformin therapy to be reported in the literature.