Adverse Effects of Donepezil in Treating Alzheimer’s Disease Associated With Down’s Syndrome

Ms. A, a 59-year-old woman with Down’s syndrome, demonstrated evidence of progressive cognitive impairment over 2 years, which was manifested as consistent confusion but without aggressive behavior. She started treatment with donepezil, 5 mg/day, and after 8 weeks, she had improvement in mood and was less confused. Ms. A’s dose of donepezil was increased to 10 mg/day, and 2 weeks later, she became agitated and aggressive. Her donepezil treatment was then discontinued, resulting in decreased agitation and aggression.

Mr. B, a 57-year-old man with Alzheimer’s disease associated with Down’s syndrome, demonstrated poor short-term memory and impulsive behavior for several months. He had difficulty with basic activities such as dressing. He started donepezil treatment, 5 mg/day, and after 4 months, he developed urinary incontinence and became increasingly forgetful. His donepezil treatment was discontinued; his urinary incontinence stopped, and he returned to baseline cognitive functioning.

Ms. C, a 65-year-old woman with Down’s syndrome with depression, apathy, and obsessive-compulsive features that were unresponsive to multiple antidepressants, started treatment with donepezil at 5 mg/day. She developed urinary incontinence that stopped when the treatment with donepezil was discontinued.