Polypharmacy and Deprescribing

Prescribing is a well-known term used to describe the act of ordering a treatment, typically a medication to treat a disease or symptom.  As a person ages they tend to accumulate what I refer to as the three “Ds”:  Doctors, Diagnoses, and Drugs.  The accumulation of drugs can lead to what is known as polypharmacy.  While not all polypharmacy is clinically inappropriate, the accumulation of drugs in an elderly patient can have significant negative effects.  Older adults with two or more disease states are likely to experience polypharmacy, generally defined as taking five or more medications.

However, not all polypharmacy is bad.  A good example of appropriate polypharmacy might be the use of 2-3 drugs to treat high blood pressure and another 2-3 drugs to treat diabetes to achieve treatment goals.  However, the use of 2-3 drugs to treat hypertension in a patient who is also using (or abusing) drugs know to raise blood pressure (i.e. non-steroidal anti-inflammatory drugs such as ibuprofen, naproxyn) may be inappropriate polypharmacy.  Simply reducing the dose or discontinuing the drugs known to raise blood pressure may reduce the number of drugs need to bring the blood pressure back down to goal.

Remember any symptom in an elderly patient should be considered a drug-related side effect until proven otherwise.

Some of the risks for polypharmacy in the elderly include

• Age-related physiologic changes
  • Reduced blood flow to the liver leading to decreased drug metabolism and toxicity
  • Worsening kidney function, blood pressure, and or heart failure with the chronic use of non-steroidal anti-inflammatory drugs (NSAIDs) in older patients with diminished renal function or a history of heart failure.  OBTW, worsening heart failure can lead to reduced blood flow to the liver (see point above)
• Presence of complex comorbid conditions requiring the use of multiple medications. This increases the risk of
  • Drug-drug and drug-disease interactions and adverse effects
  • Patient non-adherence which often results in not taking a drug but may also include taking the wrong dose or a drug that should not be used (i.e. non-prescription drugs, herbals, supplements). Another example of a drug that should not be used is one that was saved from a prior illness “just in case”.
  • Prescribing cascade or the use of additional medications to treat adverse effects of an existing medication e. the example above where additional medications are need to treat high blood pressure in a patient using excessive NSAIDs (prescription or non-prescription)
• Efficacy and safety of medications are not always well established in older patients. The benefit may be lower and the risk of side effects greater in the elderly

So what can patients and caregivers do to mitigate the negative effects of polypharmacy?  One viable option is deprescribing or assessing the benefits and risks of medications, followed by a process of tapering, stopping, or withdrawing medications that are no longer required or that have potentially harmful consequences for the individual patient.

Geriatricians and geriatric pharmacists are experts in the art and science of deprescribing.  A five-step sequential deprescribing protocol has been proposed in Australia and includes ascertaining, for each patient’s medications,

1. The reason for its use
2. Its overall risks for possible harm
3. Its current or future potential for benefit versus likelihood for harm
4. Its priority for discontinuation (with the lowest benefit-to harm ratio and the lowest likelihood of adverse withdrawal reactions)
5. Implementing a discontinuation plan with close monitoring for improvement of outcomes or onset of adverse effects

Reference

1. Jetha S Polypharmacy, the Elderly, and Deprescribing The Consultant Pharmacist September 2015