ObjectiveComprehensively characterize subjective otologic adverse events following teprotumumab administration with standardized patient reported outcome metrics. Understand the impact on patients' quality of life and perception of the medication.Study DesignRetrospective case series.SettingTertiary referral center.PatientsThirty-two adults with thyroid eye disease treated with teprotumumab from 2020 to 2023.Main Outcome MeasuresSubjective hearing loss, tinnitus, dizziness (Dizziness Handicap Inventory), patulous eustachian tube (Eustachian Tube Dysfunction Questionnaire-7, Patulous Eustachian Tube Handicap Inventory-10), effect of hearing loss on quality of life, and decisional regret.ResultsHalf reported hearing loss (n = 16, 50%) while receiving teprotumumab. Onset was gradual in 75% of patients with onset at the sixth [IQR 5-7] infusion. It was nonfluctuating (93.8%), bilateral (100%), and did not return to baseline (93.8%). Of those reporting hearing loss, 37.5% reported dizziness and 87.5% reported tinnitus; 87.5% felt it affected quality of life, and 33.3% would opt to not receive the medication again. The median DHI score was 9 [0-35] in those with hearing loss compared to 0 [0-5] in those without hearing loss (p = 0.02, Wilcoxon rank sum). Based on the ETDQ-7, 37.5% of patients experienced eustachian tube dysfunction; 15.6% experienced symptoms of a patulous eustachian tube with a median PHI-10 score of 15 [3-24], indicating a mild handicap.ConclusionsMany patients experience subjective hearing loss following teprotumumab administration, typically gradual in onset, nonfluctuating, bilateral, persistent, and significantly affecting quality of life. Patients may also experience comorbid vertigo and symptoms of eustachian tube dysfunction or patulous eustachian tube with variable severity.