Injectable long-acting risperidone was no better than was a psychiatrist’s choice of oral antipsychotic agents in forestalling hospitalization of patients with unstable schizophrenia and schizoaffective disorder, according to a report in the March 3 issue of the New England Journal of Medicine.
In a multicenter clinical trial comparing the two treatment approaches, the time to psychiatric hospitalization was no different between patients receiving risperidone injections approximately every 2 weeks and those receiving daily oral therapy. Results were the same on several standard measures of psychiatric symptoms and quality of life, and the use of other medical services also was the same.
"Taken together, these findings are consistent with [those of] 3 efficacy trials that also showed no superiority of long-acting injectable risperidone over oral regimens in patients with stable schizophrenia," wrote Dr. Robert A. Rosenheck of the Veterans Affairs New England Mental Illness, Research Education, and Clinical Center, West Haven, Conn., and his associates.
It was hoped that long-acting injectable delivery would improve treatment adherence by ensuring sustained blood levels of the drug, which would in turn improve symptom control and reduce the rate of hospitalization for relapse. Dr. Rosenheck and his colleagues tested that hypothesis in what they described as the first long-term randomized clinical trial of this formulation involving patients with unstable disease.
The study included patients with unstable schizophrenia or schizoaffective disorder who were considered at risk for rehospitalization because they were currently hospitalized (40%), had been hospitalized during the preceding 2 years (55%), or had recently increased their use of psychiatric services (5%). Most had demonstrated difficulty with medication adherence.
The study population comprised 369 older, predominantly male veterans treated at 14 sites and followed for up to 2 years.
During a mean follow-up of approximately 11 months, 81 (45%) of the 182 patients who had been randomly assigned to receive oral medication required psychiatric hospitalization, compared with 72 (39%) of 187 patients randomly assigned to receive long-acting risperidone. This difference was not significant, the investigators said (N. Engl. J. Med. 2011;364:842-51).
The time interval until hospitalization and the hospital length of stay also were not significantly different between the two study groups. Changes since baseline in patients’ total scores and subscale scores on the Positive and Negative Syndrome Scale (PANSS) also were no different. Similarly, scores on three measures of quality of life, the Clinical Global Impressions scale, and the Addiction Severity Index were similar between the two study groups.
Long-acting injectable risperidone was associated with more "general disorders and administration site conditions" such as pain or induration at the injection site, as well as with more "nervous system disorders" such as headache and extrapyramidal signs and symptoms. This suggests that patients who take oral agents "may flexibly adjust their medication use to avoid such adverse effects," Dr. Rosenheck and his associates said.
This study was supported by the VA Cooperative Studies Program and Ortho-McNeil Janssen Scientific Affairs, which also provided the injectable risperidone.