Background: A recent study reported that patients with delirium responded well to the administration of atypical antipsychotic agents. In the present study we administered quetiapine to patients with delirium and obtained good results.
Methods: This study included 24 patients (10 men, 14 women), referred to the psychiatry department during admission to other hospital departments, who were diagnosed as having delirium according to the diagnostic and statistical manual of mental disorders (4th edition) (DSM-IV) between April 2001 and September 2002. The mean age of the patients was 76.5 years (men 71.0 years; women 80.5 years). An initial dose of quetiapine was established at 25–50 mg/day. Depending on the symptoms, the dose and frequency were increased as required. According to Trzepacz's delirium rating scale (DRS), the treatment response was evaluated prior to the administration of quetiapine and 1, 3, 5 and 7 days after administration began.
Results: Prior to the administration of quetiapine, the mean DRS score was 18.1. The mean scores were 12.2, 10.8, 9.7 and 8.9 after 1, 3, 5 and 7 days of quetiapine administration, respectively. These values were significantly lower than the value before administration (P < 0.001). Seven days after the administration of quetiapine commenced, the total DRS score was lower than the cutoff point (12) in 20 patients (83.3%). In 18 patients (75.0%), delirium was clinically relieved. Doses ranged from 25 mg/day to 125 mg/day, with a mean dose of 54.7 mg/day. With respect to the administration method, the majority of patients (i.e. 13 patients) received quetiapine once per day (after dinner). Somnolence was observed in three patients as a side-effect of quetiapine administration. However, this side-effect improved after 1–2 days, without decreasing the dose.
Conclusions: Quetiapine may be useful for controlling delirium and concerning side-effects and extrapyramidal symptoms were not recorded in the present study. Thus, it is appropriate to trial quetiapine in the treatment of delirium.