Risperidone in the Treatment of Patients With Delirium

Background: The aim of this study was to evaluate the efficacy and safety of risperidone in the treatment of patients with delirium.

Method: We conducted a prospective, multicenter, observational 7-day study in 5 university general hospitals. Sixty-four patients (62.5% male [N = 40]; mean age: 67.3 ± 11.4 years) hospitalized due to a medical condition who met criteria for delirium according to DSM-IV were enrolled in the study. Fifty-six patients received 7 days of treatment or less, while 8 patients continued treatment for more than 7 days. Effectiveness was assessed using the Trzepacz Delirium Rating Scale (DRS), the positive subscale of the PANSS (PANSS-P), the Mini-Mental State Examination (MMSE), and the Clinical Global Impressions scale (CGI). Safety assessment included the UKU Side Effect Rating Scale. Risperidone was administered at the time of diagnosis, and treatment was maintained according to clinical response. Response to treatment was defined as a reduction in DRS score to below 13 within the first 72 hours. Data were gathered from April to December 2000.

Results: Risperidone (mean dose = 2.6 ± 1.7 mg/day at day 3) was effective in 90.6% (58/64) of the patients and significantly improved all symptoms measured by the scales from baseline to day 7 (mean scores: DRS, 22.5 ± 4.6 at baseline to 6.8 ± 7.0 at day 7; PANSS-P, 21.5 ± 8.8 to 10.1 ± 7.3; MMSE, 13.1 ± 10.9 to 26.4 ± 8.9; and CGI, 4.5 ± 0.9 to 1.9 ± 1.2) (Friedman test, p < .001 in all cases). Two patients (3.1%) experienced adverse events, but none showed extrapyramidal symptoms.

Conclusions: Low-dose risperidone proved to be a safe and effective drug in the treatment of symptoms of delirium in medically hospitalized patients. These data provide the rationale for a prospective randomized controlled trial.