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, galantainine 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% CP 66.0-87.3), galantamine (mean: 65.8 weeks; 95% CP 55.3-76.3) and memantine (60.9 weeks; 95% CP 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% CP 361-76.2), galantainine (median time: 567 weeks; 95% CP 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.