PRESS RELEASESeptember 24, 2018

Serious events shortly after starting dementia drugs are dose-related: study

  • September 24, 2018

September 24, 2018  |  Download Release


TORONTO, SEPTEMBER 24, 2018 – Patients with dementia prescribed a higher-than-recommended dose of ­cholinesterase inhibitors (ChEIs) therapy were more likely to have a serious event within 30 days than those dispensed a recommended dose, according to a new study by researchers at the Institute for Clinical Evaluative Sciences (ICES) and Women's College Hospital (WCH).

ChEIs are some of the only medications approved for the symptomatic management of Alzheimer’s disease and related dementias.

The study used administrative health data housed at ICES to track 80,332 Ontario seniors aged 66 and older with dementia who were newly dispensed oral ChEIs (donepezil, galantamine, rivastigmine) between 2010 and 2016. The researchers found the majority (88 per cent) were prescribed the recommended starting dose however, 7.3 per cent were prescribed a higher-than-recommended starting dose.

“Our study shows that within 30 days, an event serious enough to result in an emergency department visit, inpatient hospitalization, or death was higher in those receiving a higher-than-recommended dose of these drugs versus those receiving the recommended dose. Our data are among the first to suggest that these serious events are dose-related,” says Dr. Paula Rochon, senior author on the study, vice-president of research at WCH and scientist at ICES.

The study published today in the Journal of the American Geriatrics Society, shows that if 22 women were prescribed a ChEI at a higher-than-recommended dose (compared to the recommended starting dose) this would result in one woman having a serious event within 30 days. For men, the data showed that for every 36 men prescribed a ChEI at a higher-than-recommended dose, one man would have a serious event within the first 30 days of initiating the drug. The most common event was an emergency department visit.

“Women are at a higher risk of developing a dose-related serious event. This is an opportunity to consider both dose and sex to improve drug safety when initiating cholinesterase inhibitor therapy to manage dementia,” adds Rochon.

The researchers add that these findings reinforce the accepted strategy in geriatric medicine to “start low and go slow” to minimize adverse events that individuals starting a new drug therapy experience because adverse events are often dose related and usually occur soon after drug initiation. 

“Initial Cholinesterase Inhibitor Therapy Dose and Serious Events in Older Women and Men,” was published today in Journal of the American Geriatrics Society.



About Women’s College Hospital 

For more than 100 years Women’s College Hospital (WCH) has been developing revolutionary advances in healthcare. Today, WCH is a world leader in the health of women and Canada’s leading, academic ambulatory hospital. A champion of health equity, WCH advocates for the health of all women from diverse cultures and backgrounds and ensures their needs are reflected in the care they receive. It focuses on delivering innovative solutions that address Canada’s most pressing issues related to population health, patient experience and system costs. The WCH Institute for Health System Solutions and Virtual Care (WIHV) is developing new, scalable models of care that deliver improved outcomes for patients and sustainable solutions for the health system as a whole. 

For more information about how WCH is transforming patient care and leading health system solutions, visit

Fully affiliated with

A member of