Intramuscular Ziprasidone, 2 mg Versus 10 mg, in the Short-Term Management of Agitated Psychotic Patients

Objective: The objective of this study was toevaluate the efficacy and tolerability of the rapid-acting i.m.formulation of the novel antipsychotic ziprasidone in thetreatment of inpatients with psychosis and acute agitation(DSM-IV diagnoses).

Method: In a 24-hour, double-blind, fixed-doseclinical trial, patients were randomly assigned to receive up to4 injections (every 2 hours p.r.n.) of 2 mg (N = 54) or 10 mg (N= 63) of ziprasidone i.m. The Behavioral Activity Rating Scalemeasured behavioral symptoms at baseline and the response totreatment up to 4 hours after the first i.m. injection.

Results: Ziprasidone i.m., 10 mg, rapidlyreduced symptoms of acute agitation and was significantly moreeffective (p < .01) than the 2-mg dose up to 4 hours after thefirst injection. Patients were calmed but not excessivelysedated, and over half were classed as responders 2 hours afterthe 10-mg dose. No acute dystonia or behavioral disinhibition wasreported. One patient who received the 10-mg dose experienced theextrapyramidal side effect akathisia.

Conclusion: Ziprasidone i.m., 10 mg, is rapidlyeffective and well tolerated in the short-term management of theagitated psychotic patient. Comparison with a study of identicaldesign comparing 2-mg with 20-mg doses in patients with similarlevels of psychopathology suggests that efficacy with 10 mg or 20mg of ziprasidone i.m. is significant and dose related.