A rare case of acute renal failure secondary to rhabdomyolysis probably induced by donepezil

[Abnormal posture of the trunk related to donepezil hydrochloride: report of 2 cases]

Patient 1, an 80-year-old woman with Alzheimer's disease, had been taking donepezil 5 mg for 2 years. Donepezil was increased to 10 mg, and 2 months later, the patient developed dropped head syndrome. MRI and needle EMG abnormality of the neck extensor muscles suggested focal myopathy, but the symptom disappeared within 2 months by discontinuing donepezil. Patient 2, a 78-year-old man with Lewy body dementia, had been taking levodopa and pramipexole (PPX). One month after tapering levodopa, donepezil 3 mg was introduced, and Pisa syndrome (bending of the trunk to the right anterior direction) developed 10 days later. Donepezil and PPX were discontinued and levodopa was increased. Within 5 months, his posture had almost recovered. Cholinesterase inhibitors can induce abnormal posture of the trunk, and clinicians should be aware of this uncommon but important side effect.

Adverse Effects of Cholinesterase Inhibitors in Dementia, According to the Pharmacovigilance Databases of the United-States and Canada

This survey analyzes two national pharmacovigilance databases in order to determine the major adverse reactions observed with the use of cholinesterase inhibitors in dementia. We conducted a statistical analysis of the Food and Drug Administration Adverse Event Reporting System (FAERS) and the Canada Vigilance Adverse Reaction Database (CVARD) concerning the side effects of cholinesterase inhibitors. The statistics calculated for each adverse event were the frequency and the reporting odds ratios (ROR). A total of 9877 and 2247 reports were extracted from the FAERS and CVARD databases, respectively. A disproportionately higher frequency of reports of death as an adverse event for rivastigmine, compared to the other acetylcholinesterase inhibiting drugs, was observed in both the FAERS (ROR = 3.42; CI95% = 2.94-3.98; P<0.0001) and CVARD (ROR = 3.67; CI95% = 1.92-7.00; P = 0.001) databases. While cholinesterase inhibitors remain to be an important therapeutic tool against Alzheimer's disease, the disproportionate prevalence of fatal outcomes with rivastigmine compared with alternatives should be taken into consideration.