Hong Liu-Seifert and colleagues from Eli Lilly and Company in Indianapolis, USA, analysed the reasons for stopping treatment of patients who took part in four previous Eli Lilly studies. The studies included a total of 1627 patients and compared the effects of taking olanzapine, risperidone, quetiapine or ziprasidone in patients diagnosed with schizophrenia or related disorders.
Liu-Seifert et al.'s analysis shows that 53% (866/1627) of patients stopped treatment early. Of the 866 patients who stopped treatment, 36% (315/866) did so because the treatment was felt not to be effective or because their symptoms worsened. Only 12% of patients who stopped treatment early did so because of adverse events such as dizziness, fatigue, vomiting or weight gain.
Of the 315 patients who stopped because of poor response to treatment, 80% stopped because they themselves believed it wasn't effective. Only 20% of the patients studied stopped taking medication based on a doctor's decision that the treatment wasn't effective.
"Discontinuation due to patient perception of poor response appeared to occur particularly early in the course of treatment," the authors write. Liu-Seifert et al. found that patients who experienced an early response to medication were 80% more likely to complete treatment.
The authors' findings suggest that early and effective symptom control, and discussing expectations of treatment, may help to ensure that people suffering from schizophrenia continue to take their medication.
Discontinuation of treatment of schizophrenic patients is driven by poor symptom response: a pooled post-hoc analysis of four atypical antipsychotic drugs
Hong Liu-Seifert, David H Adams and Bruce J Kinon
BMC Medicine 2005, 3:21 (23 December 2005)