Objective: To report a case of fatal aspiration pneumonia in a patient shortly after initiation of rivastigmine and discontinuation of donepezil, with no washout period between therapies.
Case summary: An 83-year-old white man presented to the emergency department in respiratory distress (O2 saturation 70%; RR 44 breaths/min) secondary to aspiration. He had started rivastigmine 1.5 mg twice daily that same day. The patient had been previously treated with donepezil 10 mg/d, and there was no washout period. He was intubated due to worsening respiratory status and was transferred to the cardiac care unit. He then became hypotensive and required dopamine and fluid support. Brief bronchoscopy revealed food particles in the lower airways and bile-stained secretions. Intubation was notable for the large amount of secretions. The patient died approximately 27 hours after presentation to the emergency department. Blood and sputum cultures were subsequently positive for Haemophilus influenzae.
Discussion: Cholinesterase (ChE) inhibitors approved for treatment of Alzheimer disease are associated with nausea and vomiting in a sizable percentage of patients, ranging from 5% to 31% in clinical trials. Most of these adverse events occur during the initiation/titration phase of therapy. An additive risk of adverse events may be expected with coadministration of ChE inhibitors or cholinergic agents or, potentially, with an inadequate washout period between such agents. Review of MEDLINE (1966-July 2002) and International Pharmaceutical Abstracts (1970-July 2002) failed to identify any previous reports of aspiration with rivastigmine or donepezil.
Conclusions: A washout period should be considered when switching between ChE inhibitors to minimize the risk of vomiting and aspiration.