Experts have called for the classification of antipsychotic treatments as “first” or “second” generation to be abandoned after analysis showed that important differences between individual drugs are blurred by the distinction.
Researchers compared nine second-generation antipsychotic drugs with first-generation ones for overall efficacy, symptoms, relapse, quality of life, side-effects, weight gain and sedation. The meta-analysis covered 150 studies comprising more than 21,000 participants in total.
The results showed that four second-generation drugs – amisulpride, clozapine, olanzapine and risperidone – were better than first generation drugs for overall efficacy. Also, compared with the high-potency first-generation drug haloperidol, second-generation drugs induced fewer side-effects.
Apart from aripiprazole and ziprasidone, second-generation antipsychotic drugs induced more weight gain, in varying degrees, than haloperidol.
Researchers Dr Stefan Leucht, of the Technische Universitat Munchen in Germany, and Dr John Davis, of the University of Illinois in the US, wrote in The Lancet: “Because the second-generation antipsychotic drugs differ in many properties, they do not form a homogeneous class and neither do first generation antipsychotic drugs.
“Improper generalisation creates confusion and as a result the classification might be abandoned.
“This meta-analysis provides data that clinicians could use for individualised treatment of patients with schizophrenia based on efficacy, side-effects, and cost of antipsychotic drugs”.
Copyright Press Association 2008