Negative consequences associated with polypharmacy, often defined by researchers as taking five or more medications, can occur in all age populations. However, older patients are at great risk for developing such symptoms because they tend to take more medications than younger patients. In addition, they may have conditions associated with aging (such as reduced kidney function) that increase the risk for symptoms related to polypharmacy. Hypothyroidism (low thyroid function), which is also associated with advancing age, can slow the clearance of certain medications from the blood.

Other risk factors include:

• Taking dietary supplements, vitamins, over-the-counter medications and homeopathic or herbal remedies in addition to prescription medications.
  
  
• Getting prescriptions filled at more than one pharmacy.
  
  
• Having more than one doctor prescribing medications.
  
  
• Taking medications more often than once daily.
  
  
• Inability to read drug labels because of poor eyesight. People with diabetes have an increased risk of vision impairment because of diabetic retinopathy, as well as a higher incidence of cataracts and glaucoma.
  
  
• Difficulty understanding a physician’s or pharmacist’s directions because of poor hearing or language barriers.
  
  
• Difficulty remembering when to take medications.
  
  
• Making changes in diet or exercise without clearance from the physician.