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Donepezil (Aricept)

Cholinergicprescriptionoral · inferred

Centrally acting reversible acetylcholinesterase inhibitor; first-line for mild-to-severe Alzheimer's dementia and often used off-label in other dementias. Start 5 mg PO QHS; increase to 10 mg after 4-6 weeks; 23 mg ER available for moderate-severe disease. Plasma half-life ~70h supports once-daily dosing and long washout. Oral bioavailability ~100% (no food effect on extent). Extensive CYP3A4/2D6 metabolism. Cholinergic adverse effects: nausea, diarrhea, insomnia, vivid dreams, bradycardia, syncope. Being explored in longevity and cognitive-enhancement circles.

Projected serum levels — 10 mg, once daily

Donepezil (Aricept)
Donepezil (Aricept) modeled serum levels, 10 mg once daily over 23 days Population-based pharmacokinetic estimate. Steady state reached after approximately 8 days. 0 12.5 25 37.5 50 Day 0 Day 6 Day 12 Day 17 Day 23 Time on a regular schedule ≈ steady state · day 8
Donepezil (Aricept) modeled serum levels with a loading dose of 30 mg, then 10 mg once daily The first dose is larger so levels approach steady state faster. 0 12.5 25 37.5 50 Day 0 Day 6 Day 12 Day 17 Day 23 Time on a regular schedule

Maintenance schedule: 10 mg once daily (oral).

Loading schedule: 30 mg on day 1, then 10 mg once daily — reaching therapeutic levels sooner.

Modeled steady state after ~8 days: peak ≈ 45.0 mg, trough ≈ 36.2 mg body load. Population-based estimate over 23 days for a 10 mg dose at a 70 kg reference body mass — the interactive app scales curves to your doses, timing, and body mass.

Key facts

Category
Cholinergic
Route modeled
Oral
Model confidence
inferred
Half-life
2.9 days
Common dose
10 mg
Suggested maximum
23 mg/day
Reference dose range
5–23 mg (single dose)
Suggested cadence
once daily
Validated against
5 mg oral — Cmax 0.009 mg/L at 3 h

Documented interactions

  • danger
    Carbamazepine (Tegretol) + Donepezil (Aricept) CYP induction

    Carbamazepine (Tegretol) inducer of CYP3A4 predicted to change Donepezil (Aricept) AUC by ~0.31x

  • danger
    Clarithromycin (Biaxin) + Donepezil (Aricept) CYP inhibition

    Clarithromycin (Biaxin) mechanism_based of CYP3A4 predicted to change Donepezil (Aricept) AUC by ~2.00x

  • danger
    Diltiazem + Donepezil (Aricept) CYP inhibition

    Diltiazem mechanism_based of CYP3A4 predicted to change Donepezil (Aricept) AUC by ~2.00x

  • danger
    Efavirenz (Sustiva) + Donepezil (Aricept) CYP induction

    Efavirenz (Sustiva) inducer of CYP3A4 predicted to change Donepezil (Aricept) AUC by ~0.20x

  • danger
    Grapefruit (whole fruit) + Donepezil (Aricept) CYP inhibition

    Grapefruit (whole fruit) mechanism_based of CYP3A4 predicted to change Donepezil (Aricept) AUC by ~2.00x

  • danger
    Grapefruit Juice + Donepezil (Aricept) CYP inhibition

    Grapefruit Juice mechanism_based of CYP3A4 predicted to change Donepezil (Aricept) AUC by ~2.00x

Serum checks 240 modeled interaction pairings for donepezil (aricept) across your whole stack — absorption conflicts, enzyme inhibition, and nutrient depletion included.

Research behind this entry

  1. Pharmacokinetic and pharmacodynamic profile of donepezil HCl following single oral doses Tiseo PJ et al. · British Journal of Clinical Pharmacology, 1998 DOI

    First-in-human PK and pharmacodynamic study of donepezil: ~70h terminal half-life, high oral F, and AChE-inhibition time course.

  2. Donepezil improves cognition and global function in Alzheimer disease: a 15-week, double-blind, placebo-controlled study Rogers SL et al. · Neurology, 1998 DOI

    Pivotal phase 3 trial establishing donepezil 5 mg and 10 mg QD efficacy on ADAS-Cog and CIBIC-plus in mild-moderate AD.

2 published studies referenced in the app, each with a plain-language summary.