Drug use in patients with dementia: a register-based study in the health region of Girona (Catalonia/Spain)

Purpose To describe the pattern of drug consumption among patients with dementia in a geographically defined general population in Catalonia (Spain), and to determine its association with age, gender, type of dementia and severity indicators. Methods Cross-sectional study that included 1,894 cases of dementia registered by the Registry of Dementias of Girona from 2007 to 2009. Prescribed drugs were categorized according to the Anatomical Therapeutic Chemical (ATC) classification. A descriptive analysis of drug consumption was stratified according to age, gender, dementia subtypes and dementia severity. Binary logistic regression models were adjusted to detect the association of these variables with drug consumption according to the ATC groups. Results The most commonly prescribed drugs were for the central nervous system (CNS) (96.4 %), cardiovascular system (79.4 %) and digestive and metabolic system categories (77.7 %). No significant differences were found between the use of nervous system drugs and age, gender, dementia subtypes or dementia severity. The use of alimentary tract and metabolism related drugs, as well as cardiovascular and blood system drugs, were positively correlated with age and secondary dementia. The prevalence of use of cardiovascular and musculoskeletal drugs was higher in women than in men (OR: 1.34; OR: 1.26 respectively). A negative association was found between the severity of dementia and the use of musculoskeletal drugs (OR: 0.71), while its use was significantly higher in the youngest patients (OR: 1.71). Conclusions Almost all patients with dementia received a CNS drug, being at risk of inappropriate treatment. Treatment for comorbidities in patients with dementia should not be withheld on the basis of age or dementia severity, but rather on the benefit/risk ratio of its prescription. Further studies are needed to evaluate potentially inappropriate drug use and possible untreated conditions in this population.