Antipsychotic drugs are effective in psychoses, whatever the etiology of the disorder. The positive symptoms tend to respond more readily. The need for developing new drugs arises from the refractoriness of the negative symptoms, the 10-25% of the patients that are treatment-resistant and the problems of short-, and long-term extrapyramidal side-effects. Thus far, six drugs, differing from the classical antipsychotics, have been licensedfor use: olanzepine, risperidone and quetiapine; the longest registration exists for sulpiride and clozapine while the most recent one is for amisulpride. This review starts with a brief introduction to symptomatology, and takes differences with the classical drugs in pharmacology, pharmacokinetics, clinical aspects and side-effects into consideration. Clozapine, risperidone and sulpiride may be considered for clinical use in refractory patients; these three, olanzapine and amisulpride when extrapyramidal side-effects cause a clinical problem. Amisulpride and sulpiride have a dual therapeutic acion: On negative symptoms at low dose, on positive symptomen at high doses.
