Introduction
The definition of polypharmacy is not consistent throughout the literature. In some cases, it has been defined as any medical regimen containing at least one unnecessary medication (Colley et al.). In other studies, it has been defined as drug regimens containing a select number of concurrent medications (Young et al., Onoue et al.). Variations in polypharmacy definitions were explored by Masnoon et al. in their 2017 systematic review (Masnoon et al.).
Polypharmacy is an international phenomenon (Opondo et al.). In the United States, 36.8% of patients older than 65 years who went to a physician’s office between 2009 and 2016 had polypharmacy (Young et al.). In Japan, 37.2% of people aged 65–79 had polypharmacy (5+ medications). Alarmingly, 35.8% of people in this same age group were noted to have excessive polypharmacy (10+ medications) (Oneue et al.). In Ireland, 87% of individuals 75 years and older experience polypharmacy (5+ prescription drugs), and 39% of people aged 45–54 years (Tatum et al.).
Polypharmacy comes with a host of negative consequences, including increased healthcare costs, risks for adverse drug events, possibility for drug-interactions, potential for medication nonadherence, and reduced functional capacity (Maher et al.). A systematic review of international literature by Opondo et al. estimated that approximately 20% of medications prescribed to elderly individuals are inappropriate (Opondo et al.).
