Objective: To evaluate response to intramuscular (IM) aripiprazole injections using secondary analyses from clinical trials.
Methods: Data from one trial in patients with bipolar I disorder and two trials in patients with schizophrenia were assembled and used for three secondary analyses. Analysis 1 looked at data from "nonsedated" patients (i.e., patients with scores < 8 [deep sleep] or 9 [unarousable] on the Agitation-Calmness Evaluation Scale [ACES]). In analysis 2, patients were subdivided into "higher" and "lower" agitation groups according to a median split on the baseline score for the Positive and Negative Syndrome Scale (PANSS) Excited Component (PEC) (median = 18). Analysis 3 looked at the patients who received a second injection within the 24-hour study period. In each analysis, the mean change from baseline in PEC scores was re-evaluated.
Results: Analysis 1 found that nonsedated patients with bipolar I disorder and schizophrenia showed significant decreases in PEC scores following treatment with aripiprazole IM (p < 0.005). Analysis 2 found that aripiprazole IM significantly reduced agitation compared with placebo in patients with bipolar I disorder who had lower baseline agitation (p < 0.01), while patients with bipolar I disorder who had higher baseline agitation showed similarly large PEC decreases with aripiprazole (-9.9) and placebo (-7.9). Patients with schizophrenia showed significant reductions in PEC scores compared with placebo regardless of baseline level of agitation (p < 0.01). Analysis 3 found that a second injection of aripiprazole IM significantly reduced agitation in patients with bipolar I disorder or schizophrenia (p < 0.05); repeated injections were safe and well tolerated.
Conclusion: Improvements with aripiprazole IM appeared to be specific to core agitation symptoms, as opposed to nonspecific sedation, and to be independent of baseline level of agitation. Furthermore, patients benefited from a repeated aripiprazole injection when clinically warranted. These results address important clinical issues regarding use of aripiprazole IM in treating agitation.