Therapeutic Evidence - Risperidone
Han et al. A double-blind trial of risperidone and haloperidol for the treatment of delirium. Psychosomatics; 45(4) 297-301.
Study Objectives
- To compare the clinical efficacy of risperidone for the treatment of delirium.
Methods
- Design - randomized, double-blind gold-standard (haloperidol) controlled
- Allocation - although patients were said to be randomized, no description as to how randomization occurred was provided.
- Blinding - Tablets were not identical, however patients and care takers did not know the name or effects of their drug. Psychiatrist who rated patients symptoms had no information about the drugs the patient received.
- Follow-up Period - 7 days
- Setting - Single Site (Korea University Medical Centre) including 4 medical wards, 2 intensive care units and 2 oncology wards.
- Participants - (N= 28 subjects) - All patients presenting with altered mental state, based on a CAM assessment or Delirium Rating Scale, were referred to the consulting psychiatrist where a diagnosis of delirium was confirmed using the Structured Clinical Interview for DSM-III-R (SCID) according to DSM-III-R criteria. Mean ages: 66.5 (haloperidol) 65.6 (risperidone).
- Intervention - Patients either received haloperidol (starting dose 0.75mg; mean dose given 1.71mg) or risperidone (starting dose 0.5mg, mean dose given 1.02mg) twice daily. Dose was increased depending on delirium status during the 7 day treatment.
- Outcomes Assessed: Severity of delirium assessed using the Memorial Delirium Assessment Scale Scores
- Patient Follow-up - 2 patients dropped out of the haloperidol arm due to aggravation of a medical condition on the second day and one due to severe sedation on the third day. 2 patients also dropped out of the risperidone group, one due to a patient's refusal to participate in the study and one due to a tracheotomy on the fourth day.
Results
- Memorial Delirium Assessment Scale scores of each group decreased significantly during the study period (F = 53.95, df = 6, p = 0.05)
- No statistical significance seen between the the two groups (F= 0.46, df = 1, p = 0.51)
- The group by time effect was not significantly different (F = 1.66, df =6, p =0.14)
- No significant difference in the frequency of response to either haloperidol or risperidone (9 (75%) vs 5 (42%) p = 0.11)
- Side effects = one patient in the haloperidol group experienced mild akathisia, but no other patients reported clinically significant side effects.
There is no significant difference in the efficacy of delirium management with use of haloperidol versus risperidone.
Limitations
This trial did have relatively good internal validity with a detailed description of the diagnostic and assessment criteria. Although this trial did have some methodological issues such as not being able to have both drugs look identical and no details as to the randomization, the fact that the assessor was truly blinded and that the patient populations were well matched negated these issues. The main issue with regards to this study was its limited sample size. It is unclear as to whether this trial was simply not adequately powered to detect a difference between the two agents.