Preventing adverse effects of drugs



Drug interactions are a constant source of anxiety for the elderly.

According to a survey conducted in 2008 by Cara Tannenbaum, holder of the Michel-Saucier Endowed Chair in Geriatric Pharmacology, Health and Aging and researcher at the Centre de recherche de l'Institut de gériatrie at Université de Montréal, two thirds of 2,325 participants between the ages of 55 and 97 had this concern. It should be noted that 90% of people over 65 take at least one prescription drug every morning, and many take six or more.

Cara Tannenbaum hopes that her work will lead the Council to develop a provincial strategy for managing medications in the elderly.

Studies have shown that interactions between certain drugs can have serious health consequences. On this basis, the researcher undertook a project in 2010 aimed at optimizing pharmaceutical care for the elderly to prevent problems associated with these interactions.

The first phase of the project pertained to potentially inappropriate medications (PIMs). A PIM is a drug for which the risk of an adverse event outweighs its benefit, particularly when there is a safer solution for the same condition. Unfortunately, a high number of seniors consume PIMs. For example, certain sleeping pills are often prescribed even though they increase the risk of falls. A fall can lead to a long period of hospitalization, or even death in 20% of cases. Cara Tannenbaum's research team decided to set up an education program to educate seniors about the importance of managing their medication.

The researchers chose a patient-centred approach, as previous studies have shown that education interventions targeting only physicians and pharmacists are not effective. They sent 250 seniors a brochure explaining the dangers of sleeping pills and ways to avoid them. The preliminary results show that 50% of recipients expressed a desire to change their consumption habits for these medications. Results pertaining to concrete changes in behaviour will be available soon.

In the second phase of the project, the researchers developed a computer tool for identifying possible drug interactions. The program currently used by physicians and pharmacists can only analyze two drugs at once. The new tool provides a matrix showing the interactions between all of a patient's prescriptions. Once this tool is made available, practitioners will be able to minimize the risk of side-effects associated with drug interactions by eliminating or replacing certain drugs, or by changing the time intervals between doses.

The excellence of this work has been recognized by the American Geriatric Society and the Australian and New Zealand Society for Geriatric Medicine. In addition, the Institut national de santé publique du Québec has established the Conseil sur la polypharmacie, the first governmental initiative on the subject, of which Cara Tannenbaum is a participant. The researcher hopes that her work will lead the Council to develop a provincial strategy for managing medications in the elderly.