Polypharmacy in psychiatric inpatients: Data from AMSP, a European pharmacovigilance system
© Konstantinidis et al.; licensee BioMed Central Ltd. 2008
Published: 17 April 2008
Psychotropic polypharmacy is widely used in common practice although there is still a substantial deficit in established knowledge about combination and augmentation therapies. Psychiatric textbooks and international guidelines advise monotherapy wherever possible while reporting a higher risk of adverse drug reactions under polypharmacy.
Material and methods
The AMSP study is a drug safety program that ensures the continuous assessment of severe adverse drug reactions (ADR) in psychiatric inpatients under the natural conditions of routine clinical treatment. Furthermore on two reference days per hospital and per year, the following data are recorded for all patients on the wards under AMSP surveillance: all drugs applied on that day with the daily dosage for psychotropic drugs, ICD diagnosis, age, and sex. Data is stored at the study center in Munich. Due to the increasing number of participating clinics over the years only data of 33 hospitals (5 austrian, 22 german and 6 swiss institutions including university and non-university institutions) who participated since 2003 will be presented.
Between 2003 and 2005 per year over 5000 inpatient-data were recorded (2003 N=5993; 2004 N=6979; 2005 N=6400). We found a slight but steady decrease in the use of monotherapy since 2003. In detail, 2003 25,9% of the monitored inpatients were on a monotherapy with one psychotropic drug, decreasing to 24,70 % in 2004 and to 23,60% in 2005. Comparing prescriptions between the three countries, a common European trend to psychotropic polypharmacy in inpatient populations was found. Our data demonstrated that Austria had the lowest rate of monotherapy. The number of antidepressants or antipsychotics prescribed for inpatients remained stable or increased slightly over the observed years. Although the mean number of antipsychotics prescribed per inpatient remained over the years stable at 1,43, antidepressants mean number raised from 1,21 in 2003 to 1,23 in 2005. The polypharmacy was primarily due to “multipsychopharmacy”, the subscription of multiple classes of psychotropics. Details on type of drug combinations and their relative frequencies will be presented.
Although monotherapy is recommended by international experts, polypharmacy and especially multipsychopharmacy is still gaining ground. Further studies should investigate the most commonly used combinations. Special focus should be put on studies, with the purpose to evaluate assumable positive results of some psychotropic combinations.
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