Effectiveness and tolerability of high-dose (23 mg/d) versus standard-dose (10 mg/d) donepezil in moderate to severe Alzheimer's disease: A 24-week, randomized, double-blind study

Abstract

Background Currently approved Alzheimer’s disease (AD) treatments have been reported to provide symptomatic benefit, without proven impact on clinical progression. We hypothesized that the loss of initial therapeutic benefit over time may be mitigated by higher doses of a cholinesterase inhibitor. Objective The aim of this study was to determine the effectiveness and tolerability of increasing donepezil from 10 to 23 mg/d in patients with moderate to severe AD. Methods This randomized, double-blind study was conducted at 219 sites in Asia, Europe, Australia, North America, South Africa, and South America from June 6, 2007, to March 27, 2009. Patients aged 45 to 90 years with probable AD, Mini-Mental State Examination score 0 to 20 (moderate to severe impairment), and who were receiving donepezil 10 mg once daily for ≥12 weeks before the start of the study were eligible. Patients (n = 1467) were randomly assigned to receive high-dose donepezil (23 mg once daily) or standard-dose donepezil (10 mg once daily) for 24 weeks. Coprimary effectiveness measures were changes in cognition and global functioning, as assessed using least squares mean changes from baseline (LSM [SE] Δ) scores (last observation carried forward) on the Severe Impairment Battery (SIB; cognition) and the Clinician’s Interview-Based Impression of Change Plus Caregiver Input scale (CIBIC+; global function rating) overall change score (mean [SD]) at week 24. Treatment-emergent adverse events (TEAEs) were assessed using spontaneous patient/caregiver reporting and open-ended questioning; clinical laboratory testing (hematology, biochemistry, and urinalysis panels analyzed by a central laboratory); 12-lead ECG; and physical and neurologic examinations, including vital sign measurements. Results The effectiveness analyses included 1371 patients (mean age, 73.8 years; 62.8% female; 73.5% white; weight range, 34.0–138.7 kg). A total of 296 of 981 patients (30.2%) withdrew from the donepezil 23-mg/d group; 87 of 486 patients (17.9%) withdrew from the donepezil 10-mg/d group. At study end (week 24), the LSM (SE) Δ in SIB score was significantly greater with donepezil 23 mg/d than with donepezil 10 mg/d (+2.6 [0.58] vs +0.4 [0.66], respectively; difference, 2.2; P < 0.001). The between-treatment difference in CIBIC+ score was nonsignificant (4.23 [1.07] vs 4.29 [1.07]). In post hoc analysis, LSM Δ in SIB score and CIBIC+ treatment effect at end point were greater with donepezil 23 mg/d than 10 mg/d in patients with more advanced AD compared with less impaired patients (SIB, +1.6 [0.78] vs −1.5 [0.88], respectively [P < 0.001]; CIBIC+, 4.31 [1.09] vs 4.42 [1.10] [P = 0.028]). TEAEs were reported in 710 of 963 patients (73.7%) who received donepezil 23 mg/d and in 300 of 471 patients (63.7%) who received donepezil 10 mg/d. With donepezil 23 mg/d, mild, moderate, and severe TEAEs were reported in 297 (30.8%), 332 (34.5%), and 81 (8.4%) patients, respectively; with donepezil 10 mg/d, these proportions were 147 (31.2%), 119 (25.3%), and 34 (7.2%). The 3 mo...

Guidelines for the Management of Cognitive and Behavioral Problems in Dementia

“…The most commonly reported side effects with donepezil 23 mg/day were nausea vomiting, and diarrhea, which occurred at a higher incidence than with donepezil 10 mg/day. 51 Combination therapy of a ChEI and memantine is rational from a pharmacologic perspective because the agents have different mechanisms of action. In a randomized controlled trial, patients with moderate to severe AD who were already receiving donepezil derived significant benefit from the addition of memantine in terms of cognition, ADLs, global outcome, and behavior.…”

Concentration of donepezil in the cerebrospinal fluid of AD patients: Evaluation of dosage sufficiency in standard treatment strategy

“…In the EU, the maximum recommended dose is 10 mg daily, and in the USA the FDAapproved dose is 23 mg daily (Doody et al 2008;Farlow et al 2010;Noetzli and Eap 2013).…”

Could cholinesterase inhibitors be harmful over the long term?

“…As these drugs become cheaper, more widely available from generics manufacturers, and as higher doses of brand name donepezil (and memantine) are marketed with associated greater rates of adverse effects (Farlow et al, 2010), serious attention needs to be paid to the long-term effects of anti-dementia medications. Randomized controlled trials over the long term are not likely to happen unless prosecuted by government healthcare agencies.…”