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Nearly 10% of Parkinson’s patients still receiving older, typical antipsychotics despite recommendations


A new study from the Institute for Clinical Evaluative Sciences (ICES) has found that nearly 10% of Parkinson’s patients in Ontario are still being prescribed older, typical antipsychotics, despite recommendations that these patients should be receiving newer, safer atypical antipsychotics.

“Atypical antipsychotics are less likely to worsen the symptoms of Parkinson’s disease in Parkinson’s patients,” said Dr. Connie Marras, ICES research fellow and the study’s lead author.

“As such, these medications have been widely recommended by a variety of experts when drug treatment is required for the disturbing psychotic symptoms associated with Parkinson’s disease, and these have been funded by the Ontario Drug Benefit program since their introduction in 1998.

“However, up until now, there has been little information about how often antipsychotics are actually used in Parkinson’s patients, or how antipsychotic prescribing practices have changed since atypical agents have become widely available.”

To study this issue further, investigators tracked Ontarians 66 years of age and older with Parkinson’s disease who had been newly prescribed medications, between 1998 and 2003, to treat parkinsonism. Subsequent antipsychotic medications prescribed to these patients were then analyzed.

Among over 10,000 older adults newly treated with medications to treat parkinsonism, just over 1,900 were dispensed at least one antipsychotic by December 31, 2004. Within the first year of receiving medications to treat parkinsonism, about five per cent of patients were started on an antipsychotic. The estimated risk of requiring an antipsychotic at seven years was 35%. This incidence is likely to increase with disease duration and as cognitive impairment becomes more prevalent.

The results also showed that after more than four continuous years of availability and financial coverage of a preferred atypical antipsychotic in Ontario, approximately one in ten ‘first-time’ antipsychotics dispensed to individuals over 65 on medications to treat parkinsonism were still older, typical antipsychotics.

“Non-drug approaches should always be explored before starting antipsychotic therapy in Parkinson’s patients,” said Dr. Paula Rochon, study co-author, ICES scientist, and senior scientist and geriatrician at Baycrest.

“However, when drug therapy is required, atypical antipsychotics at the lowest dose possible are recommended rather than the older, typical agents.

“Clinicians need to be aware of the risk of psychosis in Parkinson’s disease, and the risks following treatment with both atypical and typical antipsychotics. More information is required to help us understand the reasons for antipsychotic prescribing choices and to determine the best strategies and interventions to improve these choices.”

The study, “Antipsychotic use in older adults with Parkinson’s disease”, is in the February 2007 issue of the journal Movement Disorders.

Author affiliations: ICES (Drs. Marras, Rochon, Mr. Kopp, Ms. Qiu, and Ms. Sykora); Morton and Gloria Shulman Movement Disorders Centre, University Health Network (Drs. Marras and Lang); Department of Psychiatry, Sunnybrook Health Sciences Centre (Dr. Shulman); Kunin-Lunenfeld Applied Research Unit, Baycrest Research Centre for Aging and the Brain(Dr. Rochon).

ICES is an independent, non-profit organization that uses population-based health information to produce knowledge on a broad range of healthcare issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting healthcare needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad, and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy.


  • Julie Dowdie,
  • Media Relations Officer, ICES
  • (416) 480-4780 or cell (416) 432-8143


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