OBJECTIVES: Behavioural and psychological symptoms of dementia such as aggressiveness, agitation and psychosis are common and very distressful for Alzheimer’s disease patients and their caregivers. Their occurrence leads to an increased use of psychotropic medications. Memantine treatment has demonstrated significant benefit on these symptoms in the experimental setting of randomized clinical trials. The objective of this study was to assess the impact of memantine treatment initiation on the use of psychotropic medications in real life practice. METHODS: A retrospective prescription claims analysis was conducted using the Quebec provincial public health plan (RAMQ) database. Data on medical and pharmaceutical services were obtained for the period from January 2004 to March 2009 for a random sample of patients who received at least one scripts of memantine. Trends in the proportion of patients using psychotropic drugs, antidepressants, neuroleptics, and anti-anxiety agents were estimated one year before and after the first prescription of memantine. RESULTS: Data were obtained from the RAMQ for a total of 2,007 patients. The study sample was 82.2 years old on average (SD = 7.6), with 67.6% of female. Proportion of patients using a psychotropic drug in the year preceding the initiation of memantine increased by 58.5%, from a proportion of 0.450 to 0.713 while this proportion only increased by 3.5% (0.713 to 0.738) in the year following the memantine initiation. The increase in proportion of users of antidepressants, neuroleptics, and anti-anxiety agents before and after initiation of memantine were 48.3% (0.239 to 0.354) vs. 2.8% (0.354 to 0.364), 112.1% (0.219 to 0.465) vs. 1.9% (0.465 to 0.474) and 41.3% (0.175 to 0.247) vs. 1.5% (0.247 to 0.250) respectively. CONCLUSIONS: Results of this prescription claims analysis indicate that the increasing rate of psychotropic drugs, antidepressants, neuroleptics, and anti-anxiety agents use significantly decrease after the initiation of memantine.