[Psychopharmacological treatment of treatment-resistant schizophrenia].

The research criteria of treatment-resistance in schizophrenia are reviewed and discussed, and the following definition for the use in the clinic is proposed: At least two periods of treatment with conventional antipsychotics from two different chemical classes at adequate doses for a period of at least four weeks, each without significant symptomatic relief. In addition, patients have to meet the criteria of clinical significant psychopathology, reduced psychosocial function or reduced quality of life. The article also reviews efficacy studies and the recommendations for the psychopharmacological treatment of therapy-resistant schizophrenia. Placebo-controlled and open trials have shown clozapine to be clearly effective in 30-60% of patients resistant to conventional antipsychotic treatment. Up to one half of the patients may respond between three months and a year of treatment. Clozapine has been found to reduce positive and negative symptoms as well as enhancing both cognitive and psychosocial function in schizophrenics. The first drug of choice today, after treatment-resistance has been established is a trial of clozapine for at least six months. The optimal dose range of clozapine appears to be 300-600 mg/day for most patients. Some schizophrenics cannot be treated with clozapine because of contraindications or do not respond sufficiently. In these patients conventional antipsychotics have to be prescribed and augmentated with benzodiazepines, antidepressants, mood-stabilizers, or electroconvulsive treatment.