Trends in the pharmacological treatment of patients with schizophrenia over a 12 year observation period

Abstract

In this study we evaluated whether our efforts to promote evidence-based guidelines for the psychopharmacological treatment of patients with schizophrenia have led to measurable changes of treatment practice in our hospital by investigating three primary hypotheses: 1) Polypharmacy has become less common in recent years, 2) Conventional neuroleptics have been replaced by second generation antipsychotics; and 3) Dosing regimes have changed towards lower doses. We have therefore collected data from the clinical records of all in-patients with ICD-9/ICD-10 diagnoses of schizophrenia hospitalized at the Department of Psychiatry of the Medical University Innsbruck in the years 1989, 1995, 1998 and 2001. Data from 1989 to 1998 showed a significant decrease in the use of two or more antipsychotics given simultaneously. Contrary to our hypothesis, there was a significant increase in polypharmacy between 1998 and 2001. The predominant use of second generation antipsychotics became standard in schizophrenia treatment. In this context the decrease of concomitant anticholinergic medication is notable. Doses of conventional antipsychotics like haloperidol as well as doses of risperidone decreased whereas doses of other second generation antipsychotics increased. All in all, the pharmacological management of schizophrenia patients is increasingly in tune with current treatment guidelines.

Introduction

During the last decade many efforts have been made towards improving strategies concerning the pharmacological treatment of patients with schizophrenia. The development of new antipsychotics and the international scientific consensus in particular about duration of treatment, dose recommendations and preference of antipsychotic monotherapy (American Psychiatric Association, 2004, Lehman and Steinwachs, 1998a, Lehmann et al., 2004, Kissling, 1991) have been the most relevant steps in this undertaking. However, the Schizophrenia Patient Outcome Research Team (PORT) data indicate discouragingly little effect of clinical guidelines for the treatment of schizophrenia in the U.S. (Lehman and Steinwachs, 1998b).

There are a number of differences between psychiatric care in Europe and in the U.S. These differences pertain mostly to resources and accessibility, especially in so far as national health care systems in Europe generally have less restrictions with regard to length of hospital stay. More different antipsychotics are available which seem to be used in combination treatments, and clozapine is prescribed in lower dosage in some European countries than in the U.S. (Fleischhacker et al., 1994). But, also within Europe, treatment strategies differ markedly (Kiivet et al., 1995, Bowers et al., 2004).

Just as Lehmann and Steinwachs (1998b) in the U.S., an earlier Austrian study (Meise et al., 1994) reflected clear discrepancies between treatment recommendations and clinical practice. As the latter was a postal survey with all the inherent limitations of this type of research, a tendency to give answers in a biased way could not be excluded.

We therefore decided to study actual clinical practice in our own hospital where treatment guidelines are an essential part of education and residency training. A preliminary analysis of data from 1989, 1995 and 1998 demonstrated an encouraging outcome concerning the efforts towards implementation of modern pharmacological schizophrenia treatment (Kurz et al., 2003). With the further investigation of more recent admissions we wanted to prove if newly registered antipsychotics influence the choice of medication, if antipsychotic dose continues to decrease and if polypharmacy becomes yet less popular, thereby lending credence to our assumption that this was indeed indicative of a continuing change towards evidence-based treatment.