Antipsychotic polypharmacy in a regional health service: a population-based study
1 Schizophrenia Clinic Program, Department of Psychiatry, Neuroscience Institute, Hospital Clinic de Barcelona, Barcelona, Spain
2 Department of Psychiatry and Clinical Psychobiology, Health Sciences Division, University of Barcelona, Barcelona, Spain
3 Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
4 Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Barcelona, Spain
5 Pharmacy Direction. Catalan Health Service, Barcelona, Spain
6 Parc Sanitari Sant Joan de Déu, Servicios de Salud Mental y Fundación Sant Joan de Déu, Red de Investigación en Actividades Preventivas y Promoción de la Salud (RedIAPP), Barcelona, Spain
BMC Psychiatry 2012, 12:42 doi:10.1186/1471-244X-12-42Published: 15 May 2012
To analyse the extent and profile of outpatient regular dispensation of antipsychotics, both in combination and monotherapy, in the Barcelona Health Region (Spain), focusing on the use of clozapine and long-acting injections (LAI).
Antipsychotic drugs dispensed for people older than 18 and processed by the Catalan Health Service during 2007 were retrospectively reviewed. First and second generation antipsychotic drugs (FGA and SGA) from the Anatomical Therapeutic Chemical classification (ATC) code N05A (except lithium) were included. A patient selection algorithm was designed to identify prescriptions regularly dispensed. Variables included were age, gender, antipsychotic type, route of administration and number of packages dispensed.
A total of 117,811 patients were given any antipsychotic, of whom 71,004 regularly received such drugs. Among the latter, 9,855 (13.9%) corresponded to an antipsychotic combination, 47,386 (66.7%) to monotherapy and 13,763 (19.4%) to unspecified combinations. Of the patients given antipsychotics in association, 58% were men. Olanzapine (37.1%) and oral risperidone (36.4%) were the most common dispensations. Analysis of the patients dispensed two antipsychotics (57.8%) revealed 198 different combinations, the most frequent being the association of FGA and SGA (62.0%). Clozapine was dispensed to 2.3% of patients. Of those who were receiving antipsychotics in combination, 6.6% were given clozapine, being clozapine plus amisulpride the most frequent association (22.8%). A total of 3.800 patients (5.4%) were given LAI antipsychotics, and 2.662 of these (70.1%) were in combination. Risperidone was the most widely used LAI.
The scant evidence available regarding the efficacy of combining different antipsychotics contrasts with the high number and variety of combinations prescribed to outpatients, as well as with the limited use of clozapine.