Rhinorrhea as a Result of Alzheimer's Disease Treatment: A Case Report.

This report describes a case of persistent rhinorrhea caused by donepezil and successfully treated with azelastine in an 84-year-old male treated with donepezil for Alzheimer's disease (AD) who experienced excessive rhinorrhea. After initiation of donepezil for AD the patient showed increased discomfort with rhinorrhea. A trial with an oral second-generation antihistamine provided no benefit. Azelastine 0.1% nasal spray was initiated and successfully reduced the rhinorrhea. A less-oftenreported side effect of donepezil that may impact patients is rhinorrhea, also described as rhinitis or nasopharyngitis.<br/> Cholinergic mechanisms of rhinorrhea have been previously described in the condition of vasomotor rhinitis and are not allergy-mediated though symptomatology overlaps. Azelastine is a histamine H1 antagonist indicated for vasomotor rhinitis. To our knowledge there are no previous descriptions in the literature that recommend azelastine to manage symptoms of rhinorrhea caused by treatments for AD. The adverse side effect of rhinorrhea, resulting from treatment with donepezil, can be disregarded as allergy symptoms. Instead, a trial of azelastine 0.1% nasal spray, one spray each nostril daily then titrated up to two sprays in each nostril twice daily as tolerated, may be warranted. Patients and caregivers should be aware of epistaxis as a potential side effect of azelastine, especially for patients on antithrombotic therapy.