[Switching patients with schizophrenia to ziprasidone from conventional or other atypical antipsychotics].

Objectives: The aim of the study was to assess the efficacy, tolerability and safety of ziprasidone in patients with schizophrenia who were already treated with conventional or other atypical antipsychotics that had to be switched due the lack of efficacy or bad tolerance.

Methods: The study was a 12-week, open label, multicenter, non comparative trial on oral ziprasidone. 106 patients with DSM-IV schizophrenia were switched to ziprasidone from their previous antipsychotic without a washout phase. The study required fixed dosing with ziprasidone. For the first week the patient received 80 mg of study drug daily, followed for 3 weeks 120 mg/day. Subsequently for 8 weeks either 80 mg, or 120 mg, or 160 mg total daily dose could be given at the discretion of the investigator. Baseline and outcome assessment included Positive and Negative Syndrome Scale (PANSS), Clinical Global Impression Severity of Illness Subscale (CGI-S) and Global Improvement Subscale (CGI-I), Calgary Depression Scale (CAD), Hamilton Depression Scale (HAMD), Drug Attitude Inventory (DAI), Simpson Angus Extrapyramidal Symptoms Rating Scale (SAS) and Barnes Akathisia Rating Scale (BARS). Changes in overall body weight were also evaluated.

Results: After 12 weeks on ziprasidone therapy, significant improvements were observed on all major symptoms measures and subscales. 34 (51,5%) patients (ITT) were rated much or very much improved on CGI-I at week 12. The mean SAS score significantly reduced during the ziprasidone treatment period (p<0.001). In the DAI ziprasidone treatment was also favorable rated. During treatment with ziprasidone for 12 weeks the body weight of the patients was significantly reduced (mean: 1,2 kg, SD=3,79, p=0.002). 58 adverse events occurred in 41 subjects (38.7%), of whom 7 patients (6.6%) encountered 9 severe adverse events. The adverse events were mainly mild and moderate. 15 patients (14.2%) were discontinued from the study due to adverse events. The reason for discontinuation in 4 cases was mainly insufficient clinical response.

Conclusion: Switching patients from their previous antipsychotic to ziprasidone without a washout phase was generally well tolerated and was associated with symptoms improvements 12 weeks later. At least 50% of patients who needed to be switched because of unsatisfactory efficacy or poor tolerance were significantly improved on ziprasidone therapy. The favorable safety profile of ziprasidone treatment was consistent with that seen in other clinical trials.

Keywords: switching, ziprasidone, schizophrenia.