Antipsychotic - ziprasidone
The first medicine to treat schizophrenia, chlorpromazine, was introduced more than 50 years ago, but although it is effective in controlling the symptoms, it has limiting side-effects. Haloperidol, launched a few years later, has fewer side-effects. But perhaps the biggest breakthrough was the first atypical antipsychotic, clozapine. Atypical antipsychotics have much lower side-effect profiles, and have revolutionised the treatment of schizophrenia.
Ziprasidone, developed by Pfizer, is a further addition to the arsenal of atypical antipsychotics. In a 28-week study in 300 outpatients with stable schizophrenia, the effectiveness of ziprasidone was compared with the conventional antipsychotic haloperidol.1 In the double blind multicentre parallel group study, the patients were give 80 to 160mg a day of ziprasidone, or 5 to 15mg/day of haloperidol. Significantly more patients were categorised as negative symptom responders in the group given ziprasidone, and these patients benefited from significant improvement in movement disorders.
A recent study focused on the effectiveness of switching to ziprasidone in schizophrenic patients with stable but symptomatic disease. Many such outpatients experience persistent symptoms or side-effects with their current antipsychotic regimen.2 A total of 270 such patients who were on a conventional antipsychotic, olanzapine or risperidone were switched to an open label six week flexible dose trial of ziprasidone, being given 40 to 160mg/day, and randomly assigned to one of three different switching schedules. All three strategies were well tolerated in all three patient groups. After six weeks' treatment with ziprasidone, significant improvements were seen on all major symptom measures. The study suggests that patients who partially respond to these therapies may find their symptoms are better controlled with ziprasidone.
It has also been investigated as a possible treatment for acute bipolar mania. A total of 210 patients undergoing an manic or mixed episode were given 40 to 80mg/day of ziprasidone twice a day, or placebo, in a double blind trial.3 Rapid and sustained improvements were seen in the patients given ziprasidone, with significant improvements typically being observed within two days of treatment commencing, and these were maintained throughout the three week treatment period. It was well tolerated and few extrapyramidal symptoms were observed.