Extemporaneous combination of donepezil and memantine to treat dementia in Alzheimer disease: evidence from Italian real-world data.

OBJECTIVE: Providing evidence on donepezil and memantine administration as extemporaneous combination (DM-EXT) to treat Alzheimer Disease (AD) in Italy, and describing demographic and clinical features of AD patients prescribed DM-EXT.

METHODS: Retrospective observational study using IQVIA Italian LifeLink Treatment Dynamics (LRx) and Longitudinal Patient Database (LPD). Prevalent users of DM-EXT were identified on the databases (cohorts DMpLRx and DMpLPD ) including patients with donepezil and memantine overlapping prescriptions during the selection period (DMpLRx : July 2018-June 2021'; DMpLPD : 'July 2012-June 2021'). Demographic and clinical profile of patients were provided. Starting from cohort DMpLPD , new users of DM-EXT were selected to calculate treatment adherence. Three additional cohorts of prevalent users of DM-EXT were identified on IQVIA LRx over subsequent 12-month periods, from July 2018 to June 2021, to get national-level yearly estimates accounting for database representativeness.

RESULTS: Cohorts DMpLRx and DMpLPD included 9,862 and 708 patients, respectively. For both cohorts, two-third of patients were female, and more than half were aged 80+. Concomitant conditions and co-treatments prevalence was very high; most frequent comorbidities included psychiatric and cardiovascular diseases. An intermediate-to-high adherence was observed in 57% of DM-EXT new users. National-level yearly estimates showed an increasing trend (+4%) in DM-EXT prescription, which led to estimate about 10,000 patients being treated during the period 'July 2020-June 2021'.

CONCLUSIONS: Prescription of DM-EXT is a common practice in Italy. Because the administration of fixed-dose (FDCs) instead of extemporaneous combinations improves treatment adherence, the introduction of a FDC containing donepezil and memantine might enhance AD patients' management and reduce caregiver burden.