Abstract
Risperdal Consta is a new preparation of injectable risperidone registered for use in New Zealand. It is a useful preparation for people who are unwilling or ambivalent about the need to take long term treatment to manage their chronic psychotic disorder. It also appears to have benefit in patients susceptible to blood level fluctuations from standard dose. The aims of this project are to monitor uptake of this new preparation of atypical antipsychotic, capture medication usage patterns, and assess longer term outcomes for eligible Maori/Pacific patients.
Why Polynesian? The health inequalities for Maori and Pacific people are declared by a slightly increased rate of schizophrenia and an increase in the delay from onset to referral. They are significantly over represented in the group of patients treated institutionally and involuntarily. As would be anticipated, therefore, audit studies have revealed a higher likelihood of Maori and Pacific patients being prescribed injectable anti-psychotic agents.
Why Consta? Studies looking at adherence to medication in people with schizophrenia show that those who take treatment are less likely to be under compulsory status, have higher levels of insight into their disorder, are higher functioning and engage better with their treating clinicians. The use of intramuscular (depot) antipsychotics may enhance adherence and contribute to relapse prevention. They are prescribed in up to 15% of people with psychotic disorders in New Zealand. Until recently the only depots available have been the older antipsychotics, which are known to produce neurocognitive and movement side effects that further reduce patients’ capacity to function normally.
The atypical antipsychotic risperidone improves both positive and negative symptoms of schizophrenia/related psychoses when compared to older typical antipsychotics and the oral formulation has been funded in New Zealand since 1999. Studies have assessed the efficacy and safety of long-acting risperidone microspheres that aims to maintain pharmacological activity for weeks; providing consistent delivery, improved compliance and patient convenience. Efficacy up to one year has been shown, and tolerance is similar to oral risperidone. Switching to this depot has not been shown to compromise safety or symptom control.
The study. Patients will be engaged with ethnic specific Maori or Pacific mental health services in Waitemata, Auckland and Counties-Manukau DHBs; to minimise differences in service delivery, especially cultural sensitivity. Methods of measuring the impact of access to a long-acting intramuscular antipsychotic include the size of change in symptoms and side effects for a patient and their use of services/options of care (e.g. inpatient unit, rehabilitation service). Follow-up is for a minimum of 24 months irrespective of whether the patient remains on risperdal Consta. Patients may show sufficient improvement on risperdal Consta to warrant a switch to an oral preparation. As a naturalistic study, decisions on dose and choice of additional interventions will be made by the treating team.
This presentation will outline the study design and early phase implementation of a longitudinal study of the effects of using risperdal Consta for Pacific and Maori clients experiencing schizophrenia. To be included in the trial subjects must be managed by a culturally specific service in the Auckland region. Careful review of the symptoms, cognition, functionality and side effect experience is made over a one year period. Data will be analysed comparing pre-treatment situation with post-treatment outcome. The design aims to create as natural setting as possible to maximise the extension of the results into the standard treatment arena.
