Intramuscular ziprasidone compared with intramuscular haloperidol in the treatment of acute psychosis. Ziprasidone I.M. Study Group

J Clin Psychiatry. 2000 Dec;61(12):933-41. doi: 10.4088/jcp.v61n1208.


Background: This 7-day, randomized, open-label, multicenter, international study compared the efficacy and tolerability of intramuscular (i.m.) ziprasidone with haloperidol i.m. and the transition from i.m. to oral treatment in hospitalized patients with acute psychotic agitation (related to DSM-III-R diagnoses).

Method: Patients received up to 3 days of flexible-dose ziprasidone i.m. (N = 90) or haloperidol i.m. (N = 42) followed by oral treatment to day 7. After an initial ziprasidone i.m. dose of 10 mg, subsequent i.m. doses of 5 to 20 mg could be given every 4 to 6 hours (maximum daily dose = 80 mg) if needed, followed by oral ziprasidone, 80-200 mg/day. Haloperidol i.m. doses of 2.5 to 10 mg were given on entry, followed by 2.5 to 10 mg i.m. every 4 to 6 hours (maximum daily dose = 40 mg) if needed, then by oral haloperidol, 10-80 mg/day.

Results: The mean reductions in Brief Psychiatric Rating Scale (BPRS) total, BPRS agitation items, and Clinical Global Impressions-Severity scale scores were statistically significantly greater (p < .05, p < .01, and p < .01, respectively) after ziprasidone i.m. treatment compared with haloperidol i.m. treatment. Further reductions in these scores also occurred in both groups following transition to oral treatment. Ziprasidone was associated with a lower incidence of movement disorders and a reduced requirement for anticholinergic medication during both i.m. and oral treatment compared with haloperidol. Movement disorder scale scores improved with ziprasidone i.m. and oral treatment, but deteriorated with haloperidol. Other adverse events were rare with both treatments.

Conclusion: Ziprasidone i.m. was significantly more effective in reducing the symptoms of acute psychosis and was better tolerated than haloperidol i.m., particularly in movement disorders. The transition from ziprasidone i.m. to oral ziprasidone was effective and well tolerated.

Publication types

  • Clinical Trial
  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Disease
  • Adult
  • Aged
  • Antipsychotic Agents / administration & dosage*
  • Antipsychotic Agents / adverse effects
  • Antipsychotic Agents / therapeutic use
  • Brief Psychiatric Rating Scale / statistics & numerical data
  • Drug Administration Schedule
  • Female
  • Haloperidol / administration & dosage*
  • Haloperidol / adverse effects
  • Haloperidol / therapeutic use
  • Hospitalization
  • Humans
  • Injections, Intramuscular
  • Male
  • Middle Aged
  • Piperazines / administration & dosage*
  • Piperazines / adverse effects
  • Piperazines / therapeutic use
  • Psychotic Disorders / diagnosis
  • Psychotic Disorders / drug therapy*
  • Psychotic Disorders / psychology
  • Severity of Illness Index
  • Thiazoles / administration & dosage*
  • Thiazoles / adverse effects
  • Thiazoles / therapeutic use
  • Treatment Outcome


  • Antipsychotic Agents
  • Piperazines
  • Thiazoles
  • ziprasidone
  • Haloperidol