Risperdal Consta (risperidone), the first newer-generation (atypical) antipsychotic medication in a prolonged release suspension, is now approved by Health Canada for the treatment of symptoms of schizophrenia and related psychotic disorders. Administered once every two weeks by intramuscular injection, it provides consistent relief of symptoms, giving patients an alternative to daily oral medication.

Schizophrenia is a chronic, highly debilitating psychiatric disorder that typically develops in adolescence or the early 20s.

Approximately one per cent of the population - some 300,000 Canadians - have schizophrenia. People with schizophrenia occupy over 30,000 hospital beds every year in Canada. According to Statistics Canada, schizophrenia makes up the second highest number of all hospitalizations for identified mental illness. The direct and indirect costs attributed to schizophrenia in Canada total more than four billion dollars annually. Moreover, patients suffering from this disorder stay in hospital longer than any other patients except those receiving rehabilitation services.

In a one-year clinical trial of Risperdal Consta, the need for re-hospitalization decreased continuously during the course of the study, from 38 per cent prior to study entry to 12 per cent during the last twelve weeks of the study.

As many as 75 per cent of patients have difficulty taking their oral medication on a regular basis or stop taking it all together - a major challenge of current schizophrenia treatment. Regularly missed doses of antipsychotic medication can lead to relapse and a return to symptoms of schizophrenia. These include delusions and visual and/or auditory hallucinations (seeing and hearing things that don't exist). With each relapse the illness may worsen.

"In taking care of my patients, prevention of relapse and hospitalization is a major goal in the treatment of schizophrenia," says Dr. Joel Jeffries, a staff psychiatrist at the Centre for Addiction and Mental Health who has specialized in the treatment of the illness for over 30 years. "Relapses can be devastating for a schizophrenia patient and can lead to hospitalization. My experience shows that it's not unusual for relapse recovery to take up to one year - often causing patients to lose social ties and any progress they've made."

While there is no cure for schizophrenia, it can be managed in most patients when they have access to appropriate treatment and follow their prescribed medication regimen.

"When medication is taken irregularly there is a great risk of relapse into psychosis and with each relapse the illness may worsen. Long-acting injections maintain medication levels and help avoid this problem," comments Dr. Jeffries. "This new option for patients acts over a two week period, with a better side-effect profile than existing injectable medications."

The extended effect of Risperdal Consta is possible using a proprietary technology called Medisorb developed by U.S.-based Alkermes, Inc. A suspension of risperidone "microspheres" - in which the medication is encapsulated in tiny spheres of biodegradable polymer - is injected into the muscle, where they gradually degrade at a controlled rate. Risperdal Consta is stored in a refrigerated environment.

The effectiveness of Risperdal Consta was established in a 12-week, placebo-controlled study in 400 adults with schizophrenia both in inpatient and outpatient settings. Patients who received Risperdal Consta experienced significantly greater improvements in both positive (psychological disturbances "added" as a result of the disorder, such as hallucinations, delusions, suspiciousness and paranoia) and negative symptoms (normal functioning that the patient has "lost", resulting in lack of initiative and loss of normal enjoyment) than did those who were administered placebo.

The most common side effects experienced by patients taking Risperdal Consta during this 12-week study were headache, agitation, psychosis, insomnia, dizziness, rhinitis and pain. Overall, similar proportions of patients reported adverse events in the placebo and Risperdal Consta groups (80 per cent versus 83 per cent), and serious adverse events were more common in the placebo group (23.5 per cent) than in the Risperdal Consta groups (13 per cent in the 25 mg group and 14 per cent in the 50 mg group).
To date, Risperdal Consta has been approved in 58 countries around the world. In Canada, Risperdal Consta will be marketed by Janssen-Ortho Inc.