Objective: This study compared dosing and utilization patterns of the cholinesterase inhibitors (ChEIs) donepezil, rivastigmine, and galantamine in the nursing home setting.
Methods: An exploratory, retrospective analysis of prescription claims data from January 1, 2001, to March 31, 2003, was conducted using data from a nationwide network of long-term care facilities in the United States. Nursing home residents with > or =1 new prescription for donepezil, rivastigmine, or galantamine during the index period from June 1, 2001, through March 31, 2002, were identified, and those who received an index prescription for a ChEI >45 days after nursing home admission and remained in the nursing home for > or=1 year after the initiation of ChEI treatment were included in the analysis. Utilization patterns were evaluated based on prescription claims for 1 year after the initiation of therapy. The study end points were the proportions of patients discontinuing or switching ChEI therapy, the proportion reaching an effective daily dose of ChEI therapy, the mean time to effective dose, and the mean daily dosage.
Results: : Two thousand eight hundred seventy-three residents of 1417 nursing homes were included in this analysis, of whom 1906 (66.3%) were prescribed donepezil, 507 (17.6%) rivastigmine, and 460 (16.0%) galantamine. The proportion of residents who were prescribed an effective dose at any point during the 1-year study period was significantly greater for donepezil than for rivastigmine or galantamine (99.3%, 72.5%, and 65.1%, respectively; both, P < 0.001). The difference between rivastigmine and galantamine also was statistically significant (P < 0.014). Donepeziltreated residents had a significantly shorter mean time to effective dose than rivastigmine- and galantamine-treated residents (1.5, 76.7, and 99.9 days; P < 0.001). The mean daily dosage of donepezil was above the effective dose throughout the study period, whereas the mean daily dosage was below the effective dose for the first 3 months with rivastigmine and did not approach the effective dose for galantamine until month 12. ChEl therapy was discontinued during the study period by 43.1%, 46.2%, and 47.0% of donepezil-, rivastigmine-, and galantamine-treated residents, respectively. The corresponding proportions of residents switching therapy were 3.3%, 4.7%, and 2.0%.
Conclusions: The results of this study suggest that early effective dosing occurred more often with donepezil than with rivastigmine or galantamine in these nursing home residents. Almost half of residents discontinued donepezil, rivastigmine, or galantamine, whereas rates of switching from one ChEI to another were low.