Adverse Effects
Elizabeth Briand
Prescribing cascades are under-recognized as a contributor to polypharmacy among older adults, according to a recent paper published in the Journal of the American Geriatrics Society on March 28, 2024, that specifically looked at gabapentinoid-loop diuretic cascades.
By analyzing Veterans Affairs and Medicare data, researchers looked at loop diuretic use before and after gabapentinoid initiation among veterans aged 66 years or older.
“Older adults are generally at a higher risk of prescribing cascades due to polypharmacy and the presence of multiple comorbidities,” said Earl Morris, PharmD, research assistant professor at the University of Florida’s Center for Drug Evaluation and Safety and one of the study authors. “However, we observed that adults over 85 years old were at a lower risk for the gabapentinoid-loop diuretic prescribing cascade compared to those 66 years to 75 years old in this population of veterans.”
He noted that this could be due to more vigilant monitoring by health care providers for patients in this age group, as well as the experience of prescribers and deprescribing initiatives.
“In our study, the gabapentinoid-loop diuretic cascades were relatively rare, but when you consider that gabapentinoids are a very popular drug, we see that this may still affect many older adults,” said the study’s lead researcher, Matthew Growdon, MD, assistant professor of medicine at the University of California, San Francisco. “The gestalt is that [these cascades] are probably more common than we think.”
Morris agreed that prescribing cascades are fairly common, especially among older adults.
“However, the exact frequency of prescribing cascades at a population level is difficult to quantify; and the frequency can vary depending on the population, health care setting, and specific medications involved,” he said.
Significant impact on patients and health care utilization
The risks to patients who experience prescribing cascades such as the gabapentinoid-loop diuretic cascade can be significant.
“Patients end up taking more medications, which increases the complexity of their treatment regimen,” said Morris. He noted that each additional medication increases the risk of drug interactions and adverse effects. The adverse effects from additional medications also can negatively impact the patient’s daily life.
Ultimately, prescribing cascades can significantly increase health care costs, due to increased health care utilization caused by adverse effects and drug interactions.
No care provider sets out to cause or exacerbate a cascade, and the root causes of these types of incidents are varied.
“Generally, prescribing cascades happen because prescribers are responding directly to a patient’s new signs and symptoms,” said Morris. Rather than anticipating issues, he noted, prescribers may misinterpret an adverse drug reaction as a new medical condition. For example, if a patient starts a medication that causes swelling (such as gabapentinoids or dihydropyridine calcium channel blockers), the prescriber might diagnose this as a new condition requiring treatment, rather than recognizing it as an adverse effect of the original drug.
Other factors contributing to prescribing cascades may include a fragmentation of care with patients seeing a variety of physicians and experiencing a loss of patient information across systems, Growdon said.
“In some cases, it could be that the prescriber may be aware of the cascade and sees the side effects happening but decides the risk benefit is worth it because their patient needs to be on that first medication,” he said.
Reducing cascades
Pharmacists can play an important role in helping to reduce prescribing cascades and the number of individuals affected by them. According to Growdon, one key action pharmacists can take is to review medications with patients by looking at the patient’s medication list and asking if the adverse effects they’re experiencing could perhaps be caused by one of those medications.
He said pharmacists also can help by closing the knowledge gap surrounding prescribing cascades, especially the gabapentinoid-loop diuretic cascade.
“There is not a lot of attention being paid to this type of cascade,” Growdon said.
Morris noted that education can also extend to prescribers, with pharmacists informing prescribers when a new symptom might be related to an existing drug.
And pharmacists can work with prescribers to try to scale back on medications.
“They can advocate for the deprescribing of unnecessary medications, especially those that were added as part of a cascade,” said Morris. “Pharmacists can work closely with prescribers to ensure that drug-related problems are accurately diagnosed and managed without adding unnecessary medications.” ■