Objective: Second-generation antipsychotics (SGAs) have proven superior to first-generation antipsychotics regarding relapse prevention, mainly in multiple-episode patients. Practice guidelines recommend SGAs as first-line treatment particularly in first-episode patients, although evidence for this group is still limited. Accordingly, the hypothesis of whether 1-year relapse rate in first-episode schizophrenia under maintenance treatment with risperidone is lower compared to haloperidol in low dose was tested.
Method: Between November 2000 and May 2004, 1372 patients had been screened for eligibility in the inpatient facilities of 13 German psychiatric university hospitals. 159 remitted patients were enrolled after treatment of an acute first episode of schizophrenia according to ICD-10 F20 criteria. In the randomized controlled trial, double-blind antipsychotic treatment with risperidone or haloperidol was maintained in a targeted dose of 2 to 4 mg/day for 1 year. 151 patients were eligible for analysis. For 127 patients, this was a continuation trial after 8 weeks of randomized, double-blind, acute treatment with the same drugs; 24 patients were additionally randomly assigned after open acute treatment.
Results: With both antipsychotics (risperidone, N = 77; haloperidol, N = 74), no relapse evolved. Additionally, according to 2 post hoc defined measures of "marked clinical deterioration," significant differences occurred neither in the 2 respective deterioration rates (risperidone = 9%/23%; haloperidol = 8%/22%) nor in time until deterioration. Both antipsychotics were equally effective regarding significant symptom reduction and improvement in quality of life. Extrapyramidal symptoms were slightly higher with haloperidol. The overall dropout rate of 68%, however, was not significantly different between the 2 drug groups.
Conclusion: Against the background of an overall favorable outcome, the hypothesized difference between risperidone and low-dose haloperidol regarding relapse prevention could not be supported for this sample of patients with first-episode schizophrenia. Possible design-related reasons for this finding are discussed. With regard to the high dropout rate, special programs are needed to keep schizophrenia patients who are in their early acute and postacute illness course in effective and safe treatment.
Clinical trials registration: ClinicalTrials.gov identifier: NCT00159081.