Schizophrenia is a chronic nniess affecting 1% of the population and remains one of the most severe and disabling diseases in existence. Symptoms can be clustered into two major groups – positive and negative – however, cognitive deficits and mood symptoms often coexist. ventolin inhalers
Positive symptoms can be described as an excess or distortion of normal functions and include delusions, hallucinations, disorganized speech and bizarre behaviour. Negative symptoms may reflect a loss of normal functions and may involve flattening of affect, alogia, avolition, anhedonia and social withdrawal. The treatment of schizophrenia consumes approximately $2.3 billion annually in direct health care costs and an estimated $2 billion in additional support costs in Canada. Pharmacotherapy remains the mainstay of treatment and, in addition to its effects on symptoms and course of illness, is vital in reducing the deleterious impact the illness has on patients, families, health care providers and society as a whole. With the recent availability of newer antipsychotics, a broadened selection of agents is available. It is essential that practitioners be aware of the similarities and differences among these medications and of the evidence that exists to support their use and place in therapy.
HISTORY OF PHARMACOTHERAPY AND HYPOTHESES
Blockade of dopamine receptors has been the foundation of the pharmacological management of schizophrenia for nearly 50 years. Chlorpromazine, released in 1951, was the first drug therapy effective in treating psychosis. Shortly thereafter the market became saturated with a glut of compounds with comparable efficacy, differing in their potencies and side effects.