SULPIRIDE - A REVIEW OF ITS PHARMACODYNAMIC AND PHARMACOKINETIC PROPERTIES, AND THERAPEUTIC EFFICACY IN SCHIZOPHRENIA

Sulpiride is a benzamide derivative, structurally distinct front other standard antipsychotics, which binds selectively to central and perip heral dopamine D-2 and D-3-receptors. In animals, sulpiride displays n europharmacological and behavioural actions that are variously conside red predictive of typical and atypical antipsychotic activity Atypical properties include a lack of sedative and cataleptogenic effects and failure to antagonise apomorphine-induced stereotypy. In common with o ther dopamine D-2-receptor antagonists, sulpiride has a pronounced pro lactin-stimulating effect. Sulpiride displays an apparent spectrum of clinical activity which differs from that of conventional antipsychoti cs with sedative effects predominating at higher doses and activating effects at lower doses. Antipsychotic activity occurs over a dosage ra nge of 400 to 3200 mg/day, with negative symptoms responding best to l ow dosages (less than or equal to 800 mg/day) and positive symptoms to higher dosages (greater than or equal to 1200 mg/day). In terms of it s global antipsychotic efficacy sulpiride compares similarly with most conventional antipsychotics. Extrapyramidal effects (akathisia, acute dystonia and parkinsonism) have been associated with sulpiride, occur ring in 12.8% of patients receiving doses less than or equal to 1200 m g/day; tardive dyskinesia appears to be rare. Male impotence, galactor rhoea and amenorrhoea are presumably related to the hyperprolactinaemi c effect of the drug. As a disinhibiting antipsychotic, sulpiride is i ndicated for the treatment of acute and chronic schizophrenia with pro minent autistic and affective symptoms. The wide therapeutic dose rang e and lack of sedative effect of low close sulpiride may be beneficial in maintenance therapy of remitted schizophrenic outpatients. With it s relatively low propensity to cause extrapyramidal symptoms and tardi ve dyskinesia, sulpiride also offers advantages in the treatment of sc hizophrenic patients who are intolerant of conventional antipsychotics .