The availability of new atypical antipsychotics, such as risperidone, that have higher acquisition costs than conventional treatments has prompted pharmaco-economic evaluation of their costs and benefits. Risperidone is reported to have superior efficacy to haloperidol and similar efficacy to other atypical antipsychotics. At dosages less than or equal to 8 mg/day, risperidone is generally associated with a lower risk of extrapyramidal symptoms than conventional antipsychotics and may have a more favourable effect on cognitive function and quality of life. Overall treatment costs during the first year of risperidone treatment were lower than in the previous year in a number of studies in patients with schizophrenia, reflecting a reduction in hospitalisation, although costs slightly increased after risperidone initiation in 2 studies. Total treatment costs were not significantly different with risperidone or conventional antipsychotics in a large, pro spective naturalistic study. The use of risperidone in preference to conventional antipsychotics in patients with chronic schizophrenia has been supported by several modelled studies, including a cost-effectiveness analysis that compared risperidone and haloperidol in chronic schizophrenia and a cost-utility study that compared the drug with oral haloperidol, depot haloperidol decanoate and depot fluphenazine decanoate for 1 year's treatment of an initially hospitalised chronic schizophrenic patient with moderate symptoms, In another study, the cost-utility ratio for risperidone versus haloperidol was 24 250 Canadian dollars per quality-adjusted life year (year of costing not stated), but only drug costs were considered. Risperidone had favourable cost-benefit ratios relative to conventional antipsychotic treatment in a study that investigated a scenario in which all patients hospitalised with newly diagnosed schizophrenia received conventional antipsychotic therapy for 6 months, and then those who did not respond received a 6-month trial of risperidone or clozapine. The results of 2 limited decision-analytical models did not favour risperidone, One study compared risperidone with oral haloperidol or depot haloperidol decanoate for the outpatient treatment of a schizophrenic patient with a history of relapse and rehospitalisation. The other compared risperidone, olanzapine and oral haloperidol for the treatment of schizophrenia. Conclusions: Despite its high acquisition cost, risperidone does not increase, may even reduce, overall treatment costs of schizophrenia by reducing hospitalisation compared with standard treatment regimens. While further pharmacoeconomic evaluation of risperidone as a first-line agent is required, pharmacoeconomic data overall support its use in patients with chronic schizophrenia. Schizophrenia is a psychotic disorder that affects approximately 0.5 to 1% of the population worldwide. It is expensive to treat because the age of onset is relatively young (late teens to mid-30s), the disease is often chronic and highly disabling and there is no cure. Hospitalisation is the greatest contributor to the direct costs of schizophrenia, whereas drug expenditure generally accounts for only about 1 to 6% of costs in developed countries. Indirect costs arising from loss of productivity can be greater than direct costs. Other costs include those related to social welfare administration and criminal justice, the time spent by unpaid caregivers and the intangible costs associated with suffering. Although the exact cost of schizophrenia is difficult to determine, it has been calculated to account for 1.6 to 2.5% of total healthcare expenditure in various developed countries. Risperidone is effective against both the negative and positive symptoms of schizophrenia. About 50 to 75% of risperidone-treated patients were clinically improved (greater than or equal to 20% improvement in the Positive and Negative Syndrome Scale score) in short term comparative trials. The optimally effective dosage for patients with chronic schizophrenia is 4 to 6 mg/day; patients with first-episode schizophrenia appear to respond to lower dosages. Risperidone (4 to 8 mg/day or flexible dosages) has been reported to have superior clinical efficacy to haloperidol. In short term comparative trials, the efficacy of risperidone was not significantly different from that of zuclopenthixol, amisulpride, clozapine and olanzapine and was superior to perphenazine on some measures. Risperidone may be more efficacious against negative symptoms (e.g. apathy, flattened affect, social or emotional withdrawal and poverty of speech) than conventional antipsychotics. The drug can be efficacious in patients who are resistant to conventional antipsychotics. Some aspects of the cognitive impairment associated with schizophrenia are improved by risperidone, and it has a more favourable effect on cognitive functioning than conventional antipsychotics such as haloperidol and fluphenazine. Risperidone is generally well tolerated. At dosages less than or equal to 8 mg/day, risperidone is not associated with a significantly greater incidence or severity of extrapyramidal symptoms (EPS) than placebo. At higher dosages, the risk of EPS is greater. Importantly, risperidone less than or equal to 8 mg/day is associated with a lower risk of EPS than haloperidol. The incidence of EPS with risperidone is similar to that with perphenazine and amisulpride, and similar to or greater than that with clozapine. Patients treated with risperidone are less likely to require concomitant antiparkinsonian medications than those receiving haloperidol or zuclopenthixol. Other adverse events that have been reported during risperidone treatment include insomnia, anxiety, headache, orthostatic hypotension, dizziness, tachycardia, bodyweight gain, somnolence/sedation, sexual dysfunction, nausea/vomiting and hyperprolactinaemia. However, the relationship of many of these events to the drug has not been established. Unlike clozapine, risperidone is not associated with significant haematological toxicity and has a low convulsant potential. The tolerability of risperidone is generally similar to or better than that of haloperidol. Risperidone appears to improve quality of life. Scores on the Global Assessment of Functioning or Quality of Life scale improved after the initiation of risperidone in 2 noncomparative studies involving a total of approximate to 1,500 evaluable patients. Quality of Life scale scores improved with both risperidone and olanzapine in another study, with no significant difference in the mean change in total scores between the drugs. In a small and very limited study, the mean score on the Munich Quality of Life Dimensions List was significantly better in patients receiving risperidone than those receiving conventional antipsychotics. In addition, 2 large studies that have not yet been published in full suggest that initiating treatment with risperidone. rather than conventional antipsychotics, after a relapse produces greater improvement in some aspects of quality of life.
