Delayed-onset hypnopompic visual hallucinations 20 years after initiation of propranolol therapy for systemic hypertension: a case report

• Main Authors: Au Eong, Denise T. M., Chiew, Ryan L. J., Au Eong, Kah-Guan
• Other Authors: Lee Kong Chian School of Medicine (LKCMedicine)
• Format: Article
• Language: English
• Published: 2024
• Subjects: Medicine, Health and Life Sciences; Charles Bonnet syndrome; Hallucinations
• Online Access: https://hdl.handle.net/10356/181393
• Institution: Nanyang Technological University

BACKGROUND Visual hallucinations occur in a variety of clinical settings and may be extremely troubling to individuals experiencing them. We report a case of delayed-onset visual hallucinations 20 years after initiation of medical therapy to highlight the importance of considering iatrogenic causes when managing such patients. CASE REPORT An 88-year-old woman presented with recurring hypnopompic formed visual hallucinations for the past 20 years. These hallucinations began 20 years after she was started on propranolol to treat her systemic hypertension 40 years earlier. Her hallucinations began with plants and insects. They later progressed to vivid, detailed human figures of different races, ages, genders, and religious personnel such as monks, nuns, and priests. The hallucinations occurred almost daily and upon awakening from sleep. Each episode of visual hallucinations lasted for 10 to 20 seconds, occurring when she awoke after dozing off, multiple times each day. The patient became mentally distressed by her visual hallucinations and began to attribute them to supernatural causes. After substituting her propranolol with atenolol, the patient's hallucinations decreased dramatically and became rare and non-frightening. The dramatic improvement suggested a drug-induced etiology. CONCLUSIONS Our case illustrates the importance of considering iatrogenic causes in the diagnosis of visual hallucinations and having a high index of suspicion, even if the onset of symptoms is delayed for many years after initiation of therapy. This iatrogenic condition can easily be rectified to drastically improve the quality of life in affected patients.