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Elderly Ontarians may not be getting the best drug combo to help prevent silent killer


With poor diets and growing obesity, high blood pressure or hypertension represents an increasing health risk for baby boomers and older Canadians. There are no telltale symptoms for the condition, which is why it’s known as the silent killer. Hypertension is the number one risk factor for stroke and a major risk factor for heart disease. Nearly 80,000 Canadians die of hypertension each year and of the 1.5 million elderly in Ontario, more than half suffer from it. While polytherapy (combination drug therapy) is effective hypertension treatment, the elderly may not be getting the best possible drug combos needed to save their lives.

New findings from the Institute for Clinical Evaluative Sciences (ICES) shows that physicians are prescribing some drug combinations that are less than ideal in treating hypertension. ICES scientist, Dr. Karen Tu, “although there has been an increase in the use of polytherapy, over a quarter of the drug combinations being prescribed together have not been proven to have additive blood pressure reduction effects.”

The ICES study was designed to look at prescribing patterns for treating hypertension. Over a two year period, 166,000 newly diagnosed Ontario patients, aged 66 years or older, without diabetes or other relevant co-morbidities, were followed to determine which antihypertensives were prescribed together. Overall, 27% of polytherapy prescriptions were for drugs without proven benefits in reducing blood pressure when prescribed together and the proportion did not change over time. Dr. Karen Tu, “the good news is physicians are using more polytherapy, the bad news is over a quarter of the drug combinations being prescribed are not the best.”

Today, physicians are treating elderly patients with a wide variety of drugs used in combination. The most frequently used combo is diuretics, known commonly as water pills, with ACE inhibitors. Current research shows the following are appropriate drug combos for treatment of hypertension:

  • thiazide diuretics with beta blockers or ACE inhibitors or angiotensin receptor blockers or calcium channel blockers
  • beta blockers with calcium channel blockers
  • calcium channel blockers with ACE inhibitors or angiotensin receptor blockers

Dr. Karen Tu says, “management of hypertension is critically important and efforts are becoming more aggressive, but improved physician awareness is needed to help ensure that patients benefit from a combination of drugs known to be effective in reducing blood pressure.”

Hypertension means high pressure (tension) in the arteries. Arteries are vessels that carry blood from the pumping heart to all the tissues and organs of the body. Normal blood pressure is below 120/80 and a blood pressure of 140/90 or above is considered high.

The study “Polytherapy with two or more antihypertensive drugs to lower blood pressure in elderly Ontarians. Room for improvement.” is in the August 2007 issue of the Canadian Journal of Cardiology.

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.


  • Kristine Galka
  • Media Relations Officer, ICES
  • Office: (416) 480-4780

Read the Journal Article