Acute agitation is common in patients with bipolar disorder and usually occurs during the manic phase of the illness. It is characterized by physical destructiveness, threatening gestures, verbal abuse and threatening language. To calm patients down quickly before they hurt themselves or others they are often given injections of tranquilisers or antipsychotic drugs directly into their muscles. A trial of intramuscular injections of the newest antipsychotic drug - aripiprazole - was carried out on 301 patients in the U.S. Researchers compared different doses of aripiprazole to a benzodiazepine (lorazepam) and a placebo. Both lorazepam and aripiprazole were more effective than the placebo and both drugs were as effective as each other with the most effective dose of aripiprazole being 9.75 mg.
Zimbroff, Dan L. ... [et al] - Management of acute agitation in patients with bipolar disorder Journal of Clinical Psychopharmacology April 2007, 27(2), 171-176