• delirium;
  • risperidone;
  • olanzapine;
  • DRS-R-98;
  • older age



This study compared the effectiveness of risperidone and olanzapine in the treatment of delirium.


This was a 7-day, randomized, comparative clinical trial of risperidone and olanzapine in patients with delirium. The primary outcome measure was the Delirium Rating Scale-Revised-98 (DRS-R-98).


We enrolled 32 subjects (median age, 70 years). Significant within-group improvements in the DRS-R-98 scores over time were observed at every time point in both treatment groups; however, differences in the change of the DRS-R-98 score from baseline were not significant between the treatment groups. On the first day after drug treatment, there was a trend toward greater improvement in the DRS-R-98 score in the olanzapine group compared with the risperidone group, but it did not reach statistical significance (p = 0.076). The response rates did not differ significantly between the two groups (risperidone group: 64.7%, olanzapine group: 73.3%). However, the response to risperidone was significantly poorer in patients ≥70 years of age compared with those aged <70 years. There was no significant difference in the safety profiles, including extrapyramidal symptoms (EPSs), between the two groups.


Risperidone and olanzapine were equally effective in reducing delirium symptoms. The response to risperidone was poorer in the older age group. Copyright © 2010 John Wiley & Sons, Ltd.