Which antipsychotic is better olanzapine or risperidone

Differences in the effectiveness of atypical antipsychotics revealed

Many patients with schizophrenia do not respond adequately to treatment with conventional neuroleptics. So-called atypicals promise better results, but they are significantly more expensive. Several of these atypicals are on the market in Germany. Some of them are among the top-selling drugs. The Federal Ministry of Education and Research (BMBF) has now supported a research project in which the effectiveness of the various atypicals was systematically examined as part of a literature analysis. The result: the atypicals have different effects, which can be decisive for the success of a treatment. It turned out that the active ingredient olanzapine is more effective than most other atypical drugs. When choosing an antipsychotic drug, possible side effects and costs must also be taken into account.


For the treatment of patients suffering from schizophrenia, in addition to the established, typical neuroleptics, several atypical neuroleptics have also been available since the 1990s. Neuroleptics or antipsychotics are drugs that are used to treat psychoses. Atypical drugs, which have less “typical” side effects, are marketed at great expense, so that the treating physicians are confronted with an almost unmanageable flood of information. So far, the different effectiveness within the group of atypical antipsychotics was also unclear, because some of the substances either lead to a significant gain in weight or to an increase in the serum prolactin level. It should therefore be clarified whether the better effectiveness of the atypicals compared to the cheaper typical neuroleptics justify the higher costs.

First meta-analysis of atypical neuroleptics
A research project led by private lecturer Dr. Stefan Leucht from the Psychiatric Clinic of the Technical University of Munich, which was funded by the BMBF, used a systematic evaluation of the existing literature, a so-called meta-analysis, to examine whether the atypical neuroleptics differ in their effectiveness. In addition, differences in side effects were also taken into account in the analysis, which are known in principle but have not yet been systematically documented. This meta-analysis examines the effectiveness of all atypical antipsychotics in randomized studies that directly compare two or more of these substances. This makes it the first of its kind. Leucht states: “Good systematic reviews are irreplaceable and an excellent method of gaining knowledge. Due to the current flood of information from research, meta-analyzes are indispensable. "

The evaluation of the meta-analysis for the atypicals showed that olanzapine was more effective than aripiprazole, quetiapine, risperidone and ziprasidone and that risperidone was more effective than quetiapine and ziprasidone. Clozapine was more effective than zotepine and also more effective than risperidone at doses> 400 mg / day. The authors explain the unexpected result that clozapine was no more effective than all other second-generation antipsychotics primarily through the relatively low clozapine doses in the studies. The differences in effectiveness result primarily from an improvement in the positive symptoms, i.e. in symptoms such as hallucinations or delusions, and less so in the negative symptoms, i.e. in terms of lack of drive, apathy, social withdrawal or flattening of feelings.

Broad database for valid results
For the meta-analysis, nine systematic reviews from the Cochrane Register for Schizophrenia and from Medline with randomized and blinded studies were compiled in which at least two of nine atypical antipsychotics were directly compared with one another. The analysis included 293 publications on 78 studies with 167 treatment arms and a total of 13,558 study participants. All data were independently assessed by at least three experts. The main criterion was the rate of change in the PANSS total score (Positive and Negative Syndrome Scale). In addition, the rate of discontinuation of treatment due to insufficient effectiveness was taken into account.

In the opinion of the scientists, however, the methodological limits of meta-analyzes must be taken into account when interpreting the results. In the case of treatment tailored to an individual patient, the comparatively minor differences in effectiveness must be weighed against the often larger differences in side effects. In addition, the cost of treatment should also be considered.

Contact Person:
Privatdozent Dr. Stefan Leucht
Clinic and Polyclinic for Psychiatry and Psychotherapy
TU Munich
Ismaninger Strasse 22
81675 Munich
Tel .: 089 4140-4249
Fax: 089 4140-4888
Email: [email protected]

 

Meta-analyzes and systematic reviews
A systematic review is a written report on the result of desk research. In this, all available primary studies are systematically identified, selected, critically assessed, and the results are determined and summarized descriptively or quantitatively using statistical methods (meta-analysis) for a clear thesis. A meta-analysis is a statistical method by means of which the results of various studies that deal with the same topic are quantitatively combined into one final result. This significantly increases the informative value compared to individual studies.

Positive / negative symptoms in schizophrenia
Positive symptoms are thought and perception disorders that occur as an exaggeration of normal experience. Schizophrenias with positive symptoms often start suddenly and there are no outwardly noticeable features. Characteristic positive symptoms are formal and substantive thought disorders, ego disorders, hallucinations and motor restlessness. In the case of content-related thought disorders, delusions typically occur. These are often expressed in acoustic hallucinations: Sick people hear voices.

Negative symptoms, on the other hand, are the limitations of normal experience. Schizophrenias, which are accompanied by negative symptoms, often begin insidiously. As the duration of the illness increases, the negative symptoms usually increase. These include dynamic emptying, cognitive deficits and motor deficits, such as a reduction in facial expressions and gestures. The initial symptoms of schizophrenia are very often sleep disorders, not infrequently also depressive symptoms.