N-acetylcysteine and Vitamin C oral antioxidant therapy for teprotumumab-related hearing dysfunction: case series and review of literature

We report three cases of successful treatment of teprotumumab-related hearing dysfunction with N-acetylcysteine (NAC) and ascorbic acid (Vitamin C). To investigate NACs effectiveness in the treatment of other types of auditory symptoms through a review of available literature. Three patients with thyroid eye disease (TED) developed symptoms of ear fullness and hearing loss during infusions of teprotumumab. Audiogram revealed above-normal pure tone average hearing threshold frequencies. They were treated with once-daily oral administration of 600 mg N-acetyl cysteine and 500 mg ascorbic acid (Vitamin C). All patients experienced nearly complete resolution of their ear symptoms prior to completing their teprotumumab therapy. They continued to remain symptom-free throughout the remaining teprotumumab infusions and onwards. This study showcases that antioxidant therapy with N-acetylcysteine and Vitamin C appears to be a promising, safe, and inexpensive potential treatment option for teprotumumab-related hearing dysfunction in our patient group.