Establishing a dose-response relationship for oral risperidone in relapsed schizophrenia
Niina Ezewuzie1
David Taylor2*
1 Clinical Pharmacist, Maudsley Hospital, Denmark Hill, London SE5 8AZ, UK.
2 Chief Pharmacist, Maudsley Hospital, Denmark Hill, London SE5 8AZ, UK.
* To whom correspondence should be addressed.
 |
Abstract |
|---|
For many antipsychotics, dose-response relationships remain poorly understood.
High dose treatment remains commonplace. We aimed to establish the dose-response
relationship for oral risperidone in relapsed schizophrenia. We searched the known
medical literature for fixed-dose studies of oral risperidone in this patient group.
Data recovered were used to construct graphs of dose versus response. Eighteen reports
evaluating the efficacy of oral risperidone were retrieved. Three studies used fixed
doses of oral risperidone for eight weeks in relapsed schizophrenia. The data from these
studies were included. Graphs plotted using these data strongly suggest that doses of
around 4 mg daily are optimal. A dose of 2 mg daily consistently produced a lower level
of efficacy. Doses of 6 mg or greater produced no additional benefit and doses tend to
be less efficacious at 10 mg daily and above. Frequency of extrapyramidal adverse
effects increased with dose. The optimal dose of risperidone in relapsed schizophrenia
is 4 mg daily. Higher doses are unlikely to improve efficacy and may reduce it. Adverse
movement disorders become more common.
Key Words:
risperidone, schizophrenia, antipsycotic, dose-response
