Ziprasidone for the treatment of acute manic or mixed episodes associated with bipolar disorder

Ziprasidone, a benzisothiazolyl piperazine-type atypical antipsychotic agent, has a unique receptor-binding profile. A potent antagonist of serotonin 5-HT2A and dopamine D-2 receptors, ziprasidone has an affinity for 5-HT2A receptors >10-fold higher than its affinity for D-2 receptors. Ziprasidone has been shown to be effective in the treatment of bipolar disorder in patients experiencing manic or mixed episodes. It was significantly more effective than placebo in improving manic symptoms as early as day 2 of treatment in two 3-week placebo-controlled trials as monotherapy. In a 12-week, placebo-controlled trial of patients with acute mania, ziprasidone as monotherapy showed comparable efficacy with, and fewer movement-related adverse events than, haloperidol. It has demonstrated efficacy in two 1-year open-label extension trials, both as monotherapy and in combination with lithium. Ziprasidone has a generally favourable adverse effect profile. In short-term placebo-controlled trials, there were similar discontinuation rates in active treatment and placebo recipients. While twice as many patients treated with ziprasidone compared with placebo discontinued therapy because of adverse events, the number of events was small and adverse effects were generally mild or moderate. The favourable tolerability of ziprasidone has been confirmed in long-term extension studies and its use was not associated with weight gain or dyslipidaemia. Ziprasidone-related movement disorders occurred infrequently.