Acute psychotic episodes represent critical situations during the course of schizophrenia. Olanzapine (OLZ), a second-generation antipsychotic, is efficacious in acute settings at dosages of 5 to 20 mg/d, and it can be considered a first-line treatment for patients with an acute episode of schizophrenia. The aim of this study was to evaluate the efficacy and tolerability of OLZ at a starting dose of 5 mg versus 20 mg in acute schizophrenic patients and to compare titration versus nontitration.
Fifty-one schizophrenic inpatients were randomly assigned to receive OLZ at 5 mg/d (26 patients, group 1) or 20 mg/d (25 patients, group 2) as a starting dosage during an exacerbation phase. In group 1, the OLZ dosage was increased to a mean dosage of 10.55 (± 4.00) mg/d. Group 2 received OLZ at a fixed dose of 20 mg throughout the hospitalization period.
Olanzapine was significantly and clinically effective on Brief Psychiatric Rating Scale (BPRS), Positive and Negative Syndrome Scale, PANSS positive symptoms, and Hamilton Rating Scale for Depression in both groups. There were no significant differences between groups 1 and 2 in the percent improvement in BPRS, Positive and Negative Syndrome Scale, PANSS positive symptoms, PANSS negative symptoms, or Hamilton Rating Scale for Depression; but group 2 was significantly superior in the mean percent improvement in the BPRS items of anxiety (P < 0.001) and suspiciousness (P < 0.05).
In conclusion, the higher doses evidence more efficacy on anxiety and suspiciousness, so it seems to be useful to begin therapy with a full dose of the drug to obtain the maximum effect without any significant side effects.