What baseline laboratory tests are recommended before initiating donepezil (Aricept) in an older adult with Alzheimer’s disease, and what labs or monitoring are needed after starting therapy?

Laboratory Monitoring for Donepezil (Aricept)

No Routine Laboratory Monitoring Required

Donepezil does not require baseline laboratory tests or routine laboratory monitoring after initiation. Unlike tacrine (the older cholinesterase inhibitor), donepezil has not been associated with hepatotoxicity and does not require liver function monitoring 1, 2.

Key Clinical Monitoring Points

Before Starting Donepezil

• No specific laboratory tests are mandated before initiating donepezil therapy 1, 2
• Physical examination and ECG may be considered in patients with cardiac conduction abnormalities or those taking medications that affect heart rate, as donepezil can cause bradycardia 3, 2
• Baseline cognitive assessment (MMSE, ADAS-cog, or similar) should be documented to track treatment response, though this is clinical rather than laboratory monitoring 2

After Starting Donepezil

• No routine laboratory monitoring is needed during treatment 1, 2
• Clinical monitoring focuses on adverse effects (nausea, diarrhea, vomiting, insomnia) rather than laboratory parameters 3, 2
• Monitor for bradycardia or cardiac conduction changes clinically, particularly during dose escalation 3, 2

Important Distinctions from Other Medications

The evidence provided includes monitoring recommendations for statins in diabetes patients (requiring baseline ALT measurement) 4, but this is not applicable to donepezil. Donepezil's safety profile is fundamentally different from tacrine, which required frequent liver enzyme monitoring due to hepatotoxicity risk 1.

Clinical Monitoring Schedule

• Weeks 1-4: Monitor for gastrointestinal side effects (nausea, diarrhea, vomiting) and sleep disturbances 3, 2
• Week 4-6: Assess tolerance before increasing from 5 mg to 10 mg daily 1, 2
• Months 3-6: Evaluate cognitive and functional response using standardized scales 2
• Ongoing: Monitor for adverse effects and treatment response, but no laboratory tests required 3, 1

Common Pitfalls to Avoid

• Do not order routine liver function tests as they are unnecessary and may lead to inappropriate discontinuation based on incidental findings unrelated to donepezil 1, 2
• Do not confuse donepezil monitoring with tacrine monitoring protocols, which required frequent ALT measurements due to hepatotoxicity 1
• Weight monitoring may be warranted at higher doses (15-20 mg/day), as weight loss has been reported, though this is clinical rather than laboratory monitoring 3