CMAJ • August 26, 2008; 179 (5). doi:10.1503/cmaj.071540.
© 2008 Canadian Medical Association or its licensors
All editorial matter in CMAJ represents the opinions of the authors and not necessarily those of the Canadian Medical Association.
This Article
Right arrow Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Online Appendices
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Valiyeva, E.
Right arrow Articles by Anderson, G. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Valiyeva, E., PhD
Right arrow Articles by Anderson, G. M., MD PhD
Related Collections
Right arrow Drugs: psychiatry
Right arrow Adverse drug reactions
Right arrow Dementia
Right arrowRelated Articles

Research

Effect of regulatory warnings on antipsychotic prescription rates among elderly patients with dementia: a population-based time-series analysis

Elmira Valiyeva, PhD, Nathan Herrmann, MD, Paula A. Rochon, MD MPH, Sudeep S. Gill, MD MSc and Geoffrey M. Anderson, MD PhD

From the Department of Health Policy, Management and Evaluation (Valiyeva, Rochon, Anderson), University of Toronto, Toronto, Ont.; the Institute for Clinical Evaluative Sciences (Valiyeva, Rochon, Gill, Anderson), Toronto, Ont.; the Division of Geriatric Psychiatry (Herrmann), Sunnybrook Health Sciences Centre, Toronto, Ont.; the Departments of Psychiatry (Herrmann) and Medicine (Rochon), University of Toronto, Toronto, Ont.; the Kunin-Lunenfeld Applied Research Unit, Baycrest (Rochon), Toronto, Ont.; and Providence Healthcare, Queen's University (Gill), Kingston, Ont

Correspondence to: Dr. Elmira Valiyeva, Department of Health Policy, Management and Evaluation, Faculty of Medicine, University of Toronto, 425–155 College St., Toronto ON M5T 3M6; fax 416 978-7350; elmira.valiyeva{at}utoronto.ca

Background: Three warnings of serious adverse events associated with the use of atypical antipsychotic drugs among elderly patients with dementia were sent to health care professionals in Canada. We assessed the impact of these warnings on prescription rates of antipsychotic drugs in this patient population.

Methods: We used prescription drug claims data from Ontario to calculate prescription rates of atypical and conventional antipsychotic drugs among elderly patients with dementia from May 1, 2000, to Feb. 28, 2007. We performed a time-series analysis to estimate the effect of each warning on rates of antipsychotic drug use.

Results: Before the first warning, growth in the use of atypical antipsychotics was responsible for an increasing rate of overall antipsychotic use. Each warning was associated with a small relative decrease in the predicted growth in the use of atypical antipsychotic drugs: a 5.0% decrease after the first warning, 4.9% after the second and 3.2% after the third (each p < 0.05). The overall prescription rate of antipsychotic drugs among patients with dementia increased by 20%, from 1512 per 100 000 elderly patients in September 2002, the month before the first warning, to 1813 per 100 000 in February 2007, 20 months after the last warning.

Interpretation: Although the warnings slowed the growth in the use of atypical antipsychotic drugs among patients with dementia, they did not reduce the overall prescription rate of these potentially dangerous drugs. More effective interventions are necessary to improve postmarket drug safety in vulnerable populations.


Related Articles

Highlights
Can. Med. Assoc. J. 2008 179: 393. [Full Text] [PDF]

Dans ce numéro
Can. Med. Assoc. J. 2008 179: 395. [Full Text] [PDF]

Concerns about health care warnings and their impact on prescribing behaviour
Laurence Y. Katz, MD
Can. Med. Assoc. J. 2008 179: 405-406. [Full Text] [PDF]



This article has been cited by other articles:


Home page
 Arch Intern MedHome page
L. L. Lipscombe, L. Levesque, A. Gruneir, H. D. Fischer, D. N. Juurlink, S. S. Gill, N. Herrmann, J. E. Hux, G. M. Anderson, and P. A. Rochon
Antipsychotic Drugs and Hyperglycemia in Older Patients With Diabetes
Arch Intern Med, July 27, 2009; 169(14): 1282 - 1289.
[Abstract] [Full Text] [PDF]

Home page
 CMAJHome page
L. Y. Katz MD
Concerns about health care warnings and their impact on prescribing behaviour
Can. Med. Assoc. J., August 26, 2008; 179(5): 405 - 406.
[Full Text] [PDF]