[Retrospective comparative analysis of antidementia medication persistence patterns in Spanish Alzheimer's disease patients treated with donepezil, rivastigmine, galantamine and memantine].

INTRODUCTION AND AIM: Dementia of Alzheimer type has become the most frequent type of dementia in our environment. Treatment persistence is a crucial factor to delay patient functional and cognitive impairment. The aim of the present study was to determine treatment persistence in usual care settings with four different antidementia drugs: donepezil, rivastigmine, galantamine and memantine in a cohort of patients with Alzheimer's dementia in Spain.

PATIENTS AND METHODS: An Alzheimer type dementia retrospective cohort study was performed in 13 Primary Care Health Centers in Spain. The study included patients treated between January 2000 and March 2005.

RESULTS: A total of 299 patients (44.8% female), mean age 77.9 years, were included: 101 donepezil (33.8.%), 105 rivastigmine (35.1%), 51 galantamine (17.1%) and 42 memantine (14.0%). Mean treatment duration was significantly different depending on therapy type, showing higher values for donepezil patients (mean: 83.3 weeks; 95% CI: 72.7-93.9) than for the other cholinesterase inhibitors: rivastigmine (mean: 76.6 weeks; 95% CI: 66.0-87.3), galantamine (mean: 65.8 weeks; 95% CI: 55.3-76.3) and memantine (60.9 weeks; 95% CI: 48.8-73.1), p = 0.049. Overall treatment persistence was significantly different between drugs, with again donepezil showing higher persistence (median time: 70.3 weeks; 95% CI: 49.8-90.7) than with the others drugs: rivastigmine (median time: 56.1 weeks; 95% CI: 36.1-76.2), galantamine (median time: 56.7 weeks; 95% CI: 41.1-72.3) and memantine (median time: 52.1 weeks; 95% CI: 35.2-69.1), log-rank = 10.16; p = 0.017.

CONCLUSION: This study showed significative differences in the global treatment persistence among the considered drug-cholinesterase inhibitors, showing higher persistence resulting in patients treated with donepezil compared to those who received rivastigmine, galantamine or memantine.