Division: Clinical and Behavioural Neurosciences
Program: Schizophrenia
Dr. Ric M. Procyshyn
B.Sc. (Pharm.), M.Sc. (U. Manitoba), Pharm.D., Ph.D. (UBC)
Email: rprocyshyn@bcmhs.bc.ca
Office: 604-875-2000 (4722)
Fax: 604-875-3871
Category: Clinical Associate Professor
Antipsychotic polypharmacy is the practice of prescribing more than one antipsychotic to a given patient at the same time. Current clinical practice guidelines do not support this practice and states that antipsychotic polypharmacy should be the last strategy employed to treat patients with schizophrenia. Despite this lack of endorsement, the practice of antipsychotic polypharmacy continues to increase. Our research group continues to study the prevalence, predictors, indicators and clinical outcomes associated with this practice.
In some cases, changes in plasma lipoproteins can modify the pharmacokinetics, tissue distribution, and pharmacological activity of lipophilic compounds such as clozapine. The fact that clozapine therapy, in many cases, can elevate serum lipids compelled our group to further examine what effect, if any, this dyslipidemia could have on clozapine’s serum distribution, kinetics, and clinical response. Our research findings have shown a significant positive correlation between serum triglycerides and clinical response to clozapine. We are now exploring possible mechanism(s) that underlie this finding.
With a prevalence as high as 90%, individuals with schizophrenia not only consume more nicotine than the general population but also more than individuals with other psychiatric diagnoses. Our research group has investigated: 1) the relationship between tobacco consumption and antipsychotic treatment (in terms of chlorpromazine equivalents and anticholinergic load, 2) self-reported motivations to smoke, and 3) predictors of starting to smoke in first episode patients.
As a consequence of its prevalence, early onset and chronicity, schizophrenia imposes clinical and economic impediments to healthcare practitioners. Among the armamentarium of agents available to treat the symptoms of this devastating illness, the atypical antipsychotics have received the most attention. Although these agents have proven valuable, their use has often been limited by their high acquisition costs relative to the older conventional antipsychotics. Our research on the pharmacoeconomics of the atypical antipsychotics has been successful in raising the awareness to healthcare practitioners and decision-makers alike of the challenges of providing quality care while balancing fiscal responsibility.
Our group continues to carry out trials of antipsychotics examining their effectiveness, safety and tolerability. We have just recently completed a trial that examined whether long-acting injectable risperidone is effective in reducing psychotic symptoms in treatment refractory patients.
The therapeutic use of atypical antipsychotics is associated with a high incidence of metabolic side effects. Using a rodent model, our group is currently investigating the acute and chronic effects of the atypical antipsychotics on alterations in glucose and insulin parameters with the goal of determining the mechanism(s) that underlie this phenomenon.
Procyshyn RM, Honer WG, Wu TKY, Ko RWY, McIsaac SA, Young AH, Johnson JL, Barr AM. Persistent antipsychotic polypharmacy and excessive dosing in the community psychiatric treatment setting. Journal of Clinical Psychiatry 2010;71:566-573.