Une étude pharmaco-épidémiologique observationnelle de type transversal des pratiques de prescription des antipsychotiques atypiques (APA) a été réalisée au CH Charles Perrens (Bordeaux). Elle met en évidence une relative stabilité dans le temps des pratiques de prescription des APA : les seules variations observées sont une augmentation significative des coprescriptions de normothymiques et d'anxiolytiques, une diminution significative de celle des correcteurs neurovégétatifs. Cependant, par certains points ces pratiques diffèrent en fonction des APA : la rispéridone est le médicament le plus prescrit, dans l'établissement, chez des patients psychotiques et chez des patients dont la moyenne d'âge est la plus élevée ; un hypnotique lui est le plus souvent associé. La clozapine, l'APA le moins prescrit dans l'établissement, est destinée en majorité à des patients psychotiques et est la moins associée à d'autres neuroleptiques ou à un correcteur neurologique ou à un hypnotique. L'amisulpride est le plus prescrit pour des troubles de l'humeur et le plus associé à un normothymique ou un correcteur neurologique. Enfin l'olanzapine, le deuxième APA le plus prescrit dans l'établissement, est souvent associé à un autre neuroleptique à visée sédative. Concernant la tolérance des APA, la proportion de correcteurs neurologiques coprescrits est élevée, celle des correcteurs neurovégétatifs est moindre. Ces résultats confirment la place de plus en plus importante prise par ces médicaments au détriment des anciens neuroleptiques dans le traitement des pathologies psychotiques et non psychotiques, et pour ces dernières en particulier dans les troubles de l'humeur. Ils doivent être complétés par de nouvelles études.

The commercial introduction of atypical antipsychotics (AAP) constitutes a considerable step forward in the sense that it has led to a world-wide reappraisal of the established treatment strategies for people with psychoses (including schizophrenia and affective psychoses). They have allowed refinements in the pharmacologic management of psychoses but they have a higher acquisition cost than conventional neuroleptics. The cost of the newer AAP had a substantial effect on medical resources : the AAP account for only 43.2 % of neuroleptic prescriptions, but 76.1 % of medical costs associated with neuroleptic drugs, and in terms of treatment costs, a reduction (50 %) was found with risperidone compared with olanzapine for a same number of treated patients. The aim of this paper was to examine the use of these drugs, to compare them and to assess their impact within the context of psychiatric hospital practice, by means of analysis of prescribing practices for amisulpride, clozapine, olanzapine and risperidone for all treated patients. We conducted an observational, naturalistic study at Charles Perrens psychiatric Hospital in Bordeaux (France) that reproduced the clinical conditions in which these new drugs are used. Four photographies of all the medical prescriptions concerning atypical antipsychotic drugs were done between October 1999 (four months after the introduction in France of the olanzapine, the last of the new antipsychotics) and June 2001 (n = 682 prescriptions). The total amount of these prescriptions corresponded to 527 patients. Treatment groups were compared - first overall and after by considering 2 groups : psychotic and non-psychotic patients - through descriptive analyses of sociodemographic characteristics of patients, diagnosis, percentages of patients receiving concomitant psychotropic medication and/or receiving treatment-emergent side effects and mean dosages of AAP therapy according to concomitant medication. In the same way, we compared the four AAP through their prescribing practices'evolution during the four survey. Results : AAP drugs account for 43.2 % of prescriptions (and conventional neuroleptics 56.8 % of them). We recorded a significant increase between the four surveys (p < 0.02) : 36.6 % at the beginning to 47.8 % at the end of the study. From the 682 collected prescriptions, 72 (10.6 %) included clozapine, 130 (19.1 %) amisulpride, 229 (33.6 %) olanzapine and 251 (36.8 %) risperidone. Sixty five percent of AAP prescriptions involved psychotic patients. A relative stability in characteristics of AAP prescriptions during the four surveys was found. So, no significant differences were observed between amisulpride, olanzapine, risperidone, in terms of age, sex, sociodemographic characteristics, unlike clozapine. However, there were statistical differences between all the AAP in the concurrent use of other neuroleptic agents (p < 0.02), hypnotic drugs (p < 0.006), mood stabilizer drugs (p < 0.03), and anticholinergic drugs (p < 0.007). Statistically, the mean dosage of amisulpride increased when a mood stabilizer drug was coprescribed (p < 0.0007), but it decreased with an antidepressant drug (p < 0.004) or an hypnotic drug (p < 0.02) ; clozapine 's one decreased every time an antidepressant drug was coprescribed (p < 0.02) ; with olanzapine, there was a significant increase every time an other neuroleptic agent (p < 0.03) or an anticholinergic drug (p < 0.006) was associated ; then for risperidone, the mean dosage increased with the coprescription of an other neuroleptic agent (p < 0.00002), an anticholinergic (p < 0.00003) or an adrenolytic drug (p < 0.04). The pattern of prescribing practices that emerges from our four surveys suggests that these new AAP are significantly more and more often associated with a stabilizer mood drug (p < 0.009) (particularly the olanzapine) or/and an anxiolytic drug (p < 0.05) (like the amisulpride in particular). Considering the four AAP globally, but more with the risperidone, the association with a neurovegetative corrector agent decreased (p < 0.004) during the four surveys. Then, concerning the psychotic patients, the AAP were significantly more often associated with other neuroleptic agents (p < 0.03), the amisulpride in particular, with anticholinergic drugs (p < 0.00005), but significantly less with mood stabilizer drugs (p < 0.00003) principally the amisulpride and the risperidone, with antidepressant drugs (p < 0.02) particularly the risperidone. This kind of survey, however it is too much rare, is very important because it shows the clinical conditions in which these new drugs are really used. The results show that AAP appear to be the replacements of the older neuroleptics used in the treatment of psychoses, including particularly schizophrenia, but also in the treatment of mood disorders, and they reflect actual clinical practices. Other surveys must be achieved to see if our study confirms the general trend concerning the use of these drugs and so as to reassess these prescribing practices.