Clinical Pharmacy Research

Sunnybrook Health Sciences Centre
2075 Bayview Ave.
Toronto ON M4N 3M5

Area of Research

Brian Hardy’s research focuses on the pharmacokinetics, pharmacodynamics and effectiveness of drugs in the elderly. Clinical studies conducted include examining drugs used for major depression and bipolar disease in the elderly.

Research Challenge

With an increasingly aging population, the number of drugs prescribed for the elderly vastly exceeds all other age groups. As such, the disposition and elimination of drugs in the elderly needs to be determined in order to modify their dosages compared to a younger age group, when necessary. In addition, the toxicities and effectiveness of drugs used in the elderly may differ from a younger population.

However, when a new drug comes to market, the pharmacokinetics have usually been studied in young healthy volunteers. The pharmacokinetic parameters determined in such studies are unlikely to represent how the drug is handled in elderly patients with decreased renal function and body mass, especially if they have co-morbid conditions (e.g., congestive heart failure). Yet, the primary consumers of these drugs are often older individuals who develop the targeted medical conditions over time.

Proposed Solution

For those drugs that are extensively used by the elderly, we need adequate information on any differences that may exist in their disposition, side-effect profiles and responsiveness compared to a younger population. Studies ideally need to examine a range of elderly subjects (e.g., 65–75, 75–85 and over 85 years old) compared to a younger population (e.g., under 65 years) to discern how drug disposition and responsiveness change over the aging decades.

Hardy conducts studies of drugs in the elderly to identify differences in pharmacokinetic parameters (e.g., volume of distribution, clearance and protein binding) and pharmacodynamics (e.g., increased sensitivity) compared to the young that warrant dosage modifications in an older population.

Impact to Date

Hardy has conducted trials in the elderly population for drugs used to treat major depression (e.g., lithium) and bipolar disease (e.g., valproate). These trials identified differences in pharmacokinetic and pharmacodynamics of these drugs compared to a younger population, and have resulted in a suggested dosage modification for the elderly for these medications and a lower therapeutic range for lithium in the elderly.