Intramuscular ziprasidone, 2 mg versus 10 mg, in the short-term management of agitated psychotic patients.

BACKGROUND

There is a clear need for effective, well-tolerated intramuscular (i.m.) agents for the acute control of agitated psychotic patients. Currently used agents, including conventional antipsychotics and/or benzodiazepines, may be associated with distressing side effects such as extrapyramidal side effects and excessive sedation.

OBJECTIVE

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

METHOD

In a 24-hour, double-blind, fixed-dose clinical trial, patients were randomly assigned to receive up to 4 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 Scale measured behavioral symptoms at baseline and the response to treatment up to 4 hours after the first i.m. injection.

RESULTS

Ziprasidone i.m., 10 mg, rapidly reduced symptoms of acute agitation and was significantly more effective (p < .01) than the 2-mg dose up to 4 hours after the first injection. Patients were calmed but not excessively sedated, and over half were classed as responders 2 hours after the 10-mg dose. No acute dystonia or behavioral disinhibition was reported. One patient who received the 10-mg dose experienced the extrapyramidal side effect akathisia.

CONCLUSION

Ziprasidone i.m., 10 mg, is rapidly effective and well tolerated in the short-term management of the agitated psychotic patient. Comparison with a study of identical design comparing 2-mg with 20-mg doses in patients with similar levels of psychopathology suggests that efficacy with 10 mg or 20 mg of ziprasidone i.m. is significant and dose related.