Dima Lorena 1, Vasile D. 2, Voicu V.A. 2
1 Transilvania University, Brasov, Faculty of Medicine
2 University of Medicine and Pharmacy Carol Davila Bucharest, Department of Farmacology, Toxicology and Clinical Neuropsychopharmacology
Abstract
Continuity of antipsychotic treatment is a prerequisite for obtaining maximum benefit and favourable treatment outcome. However, there are considerable differences between studies in terms of the level of discontinuation rates and the estimated time to discontinuation for different antipsychotics. In order to clarify these aspects more information is needed on treatment discontinuation in routine clinical settings. The aim of this study was to compare the rate of treatment discontinuation among patients with schizophrenia or related disorders treated with antipsychotics. Material and methods. The study was a one-year follow-up, observational study of 131 patients with schizophrenia or related disorders treated with haloperidol, olanzapine, risperidone, quetiapine, or aripiprazole. The main outcome variable measured was time in months to treatment discontinuation. Reason of discontinuation was also registered. Results. Rate of discontinuation as resulted from Kaplan-Meier univariate analysis was significantly higher in patients treated with haloperidol compared to both atypical treated group and olanzapine treated group. In Cox proportional hazards regression analysis, the group of patients with at least one previous psychotic episode was associated with a 2.5-fold increased risk of treatment discontinuation, compared to first psychotic episode patients (HR=2.571 [CI 1.077-6.139], p 0.033). After adjustment for this covariate in the Cox model, resulted HR for discontinuation with haloperidol as the reference group confirmed the order of risk of discontinuation for any reason decreasing (highest for haloperidol, lowest for olanzapine), but differences between groups did not reach the level of statistical significance. When the same analysis was performed differentiated according to specific causes, the only difference between treatment groups confirmed as statistically significant was in case of non-adherence, for olanzapine compared to haloperidol: HR= 0.109 [CI 0.013-0.923], p 0.042. Conclusion. The results of this observational study suggest that the differences between typical and atypical antipsychotics and between atypicals cannot be excluded in what persistence to treatment is concerned and that the choice of antipsychotic may be an important factor in the long term evolution in patients with schizophrenia and related disorders.