What are ADEs and Polypharmacy?

An adverse drug event, or ADE, occurs when a person is harmed due to a prescription medication. This can include known medication side effects or medication errors. About half of ADEs are considered preventable, yet they continue to pose a significant public health risk with substantial financial consequences. Approximately 1.3 million emergency visits1, 350,000 hospitalizations1, and $3.5 billion in excess medical costs2 occur annually in the United States from ADEs. The risk for ADEs increases with each medication a patient is taking, so patients taking multiple medications are at the highest risk for ADEs.

Polypharmacy occurs when a patient simultaneously takes multiple medications to treat one or more conditions. Nearly one third of adults in the United States take five or more medications3. Polypharmacy has become a significant concern in the healthcare industry, as it increases the risk for ADEs and medication failure. In extreme cases, polypharmacy can lead to death. As a result, strategies for decreasing polypharmacy and ADEs are a major focus of patients and healthcare professionals. This article will discuss how Pharmacogenomics (PGX) serves as a tool to help alleviate ADEs.

Who’s at risk?

Patients who are at the highest risk for polypharmacy include those with multiple health conditions, patients with more than one prescriber, and the elderly. In some cases, single conditions have guidelines which state that polypharmacy is a recommended treatment plan after monotherapy fails or underperforms. These conditions include hypertension, type II diabetes, and major depressive disorder. For these conditions, treatment guidelines instruct healthcare providers to add additional medications to a patient’s treatment plan when the first is inadequate. In some cases, healthcare providers may prescribe additional medications to treat the side effects of another drug. For example, a provider may prescribe an anti-nausea medication for a patient who experiences nausea as a side effect of codeine.

PGx – A Tool to Reduce ADEs and Polypharmacy

Laboratory testing is one of the most frequently used clinical tools to help providers safely and effectively manage their patients’ medications. Research shows that optimal usage of laboratory tests can decrease a patient’s risk of experiencing an ADE4. For example, a physician might order a test to monitor serum potassium levels for patients taking angiotensin-converting enzyme (ACE) inhibitors or a liver function test (LFT) for a patient on statins.

Pharmacogenomics (PGx) testing is one less frequently used clinical tool that can significantly decrease the risk of ADEs. PGx testing identifies variants in a patient’s DNA that affect how well that person responds to specific medications. PGx can help predict if a drug will be safe, effective, and non-toxic for a patient. The PGx test reduces the need for trial-and-error prescribing. Preemptive PGx testing is especially beneficial because it assists a prescriber in identifying a patient’s risk of experiencing an ADE before the medication is prescribed.

With PGx testing, a prescriber can make informed decisions that decrease the risk of polypharmacy. When a provider knows that a patient is more likely to have side effects from a medication, they can prescribe an alternative. Doing so eliminates the need for additional medications to treat the side effects of the first. A provider can also use PGx information to select a drug that is more likely to be effective for the patient. This reduces the risk of medication failure and makes it less likely that the provider will need to prescribe a second medication to treat the patient’s condition.

References

  1. Centers for Disease Control and Prevention. (2017). Adverse Drug Events in Adults. Retrieved from https://www.cdc.gov/medicationsafety/adult_adversedrugevents.html. Accessed January 06, 2023.
  2. Institute of Medicine. (2007). Committee on Identifying and Preventing Medication Errors. Retrieved from https://nap.nationalacademies.org/read/11623/chapter/2#4. Accessed January 06, 2023.
  3. Medication Errors and Adverse Drug Events. (2019). Agency for Healthcare Research and Quality. Retrieved from https://psnet.ahrq.gov/primer/medication-errors-and-adverse-drug-events. Accessed January 06, 2023.
  4. Jackevicius CA and Glassman P. (2014). Laboratory monitoring for pharmaceuticals: familiarity does not breed contempt. Journal of general internal medicine, 29(12), 1574-1576. doi.org/10.1007/s11606-014-3048-x