Electrocardiographic monitoring for new prescriptions of quetiapine co-prescribed with acetylcholinesterase inhibitors or memantine from 2005 to 2009 : a population study on community-dwelling older people in Italy

Purpose: The aims of this study are to analyse, in community-dwelling people aged 65+ living in Italy's Lombardy Region, electrocardiographic (ECG) monitoring for new users of the atypical antipsychotic quetiapine co-prescribed with acetylcholinesterase inhibitors (AChEIs) or memantine and to find independent predictors of ECG monitoring before and after the starting of this prescription. Methods: The Lombardy Region's administrative health database was used to retrieve prescriptions of ECG exams as well as prevalence rates of subjects aged 65+ who were prescribed such psychotropic drugs from 2005 to 2009. Multivariable analyses were adjusted for age, sex, number of drugs, treatment with beta-blockers, digoxin, verapamil or diltiazem, any antiarrhythmic drug and antidepressants. Results: Overall 2,623 community-dwelling older people started therapy with quetiapine, co-prescribed with AChEIs or memantine, during these 5 years. At least one ECG was performed in 714 cases (27.2 %) in the 6 months before - and in 398 cases (15.2 %) within 3 months after - the starting of this prescription. ECG monitoring was performed both before and after starting quetiapine in only 160 cases (6.1 %). At multivariable analyses, number of drugs taken, beta-blocker and antiarrhythmic drug use were found to be independent correlates of ECG monitoring whereas female sex was associated with a lower probability of receiving an ECG within 3 months after the initiation of quetiapine (odds ratio 0.78, 95 % CI 0.62-0.98). Conclusions: ECG monitoring for new prescriptions of quetiapine in older people suffering from behavioural and psychological symptoms in dementia was actually performed infrequently, independently of the age of drug users, especially in women. Our results support the need for greater awareness within the medical community of the importance of such ECG monitoring.