Prescribing Cascades: Polypharmacy in Older Adults
Unraveling Prescribing Cascades: New Insights from a Large-Scale Irish Study
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A recent study analyzing prescription data from ireland has shed new light on the complex phenomenon of prescribing cascades,particularly among older adults. The research, which examined over 46 million index and marker medication prescriptions dispensed in 2020, identified several common medication sequences that may indicate a prescribing cascade, where a new drug is prescribed to manage a side effect of an existing drug, potentially leading to further medication use.
Understanding Prescribing Cascades in Older Adults
Prescribing cascades are a significant concern in geriatric pharmacotherapy, contributing to polypharmacy and increasing the risk of adverse drug events. these cascades occur when a drug-induced symptom or sign is misinterpreted as a new medical condition, leading to the prescription of another medication. The study, which observed prescription patterns from 2018 to 2020, found a wide range in the number of incident users for various medication classes. As a notable example, alpha-1 receptor blockers saw 17,078 incident users, while nonsteroidal anti-inflammatory drugs (NSAIDs) had a much larger cohort of 137,280 incident users.
Key Findings: Positive Associations and Decreases
The investigators identified five significant ”dyads” – pairs of medications where the initiation of the first (index) medication was positively associated with the subsequent prescription of the second (marker) medication. These associations suggest a potential prescribing cascade:
Calcium channel blockers followed by diuretic prescribing: This suggests that diuretics might be prescribed to manage edema,a known side effect of some calcium channel blockers.
Antipsychotics leading to antiparkinsonian agents: This highlights the common practice of prescribing medications for drug-induced parkinsonism, a side effect of antipsychotics.
Benzodiazepines leading to antipsychotic prescribing: This could indicate the use of antipsychotics to manage agitation or psychosis that may arise from benzodiazepine withdrawal or long-term use.
Selective serotonin reuptake inhibitors (SSRIs) or selective norepinephrine reuptake inhibitors (SNRIs) leading to sleep agents: This points to the potential use of sleep medications to manage insomnia, a common side effect of antidepressant therapy.
Alpha-1 receptor blockers leading to vestibular sedative medication: This suggests that medications for dizziness or vertigo might be prescribed to address side effects associated with alpha-1 receptor blockers.
Conversely, the study also noted a decrease in prescriptions for certain dyads, indicating a potential shift away from these cascade patterns:
Diuretic to overactive bladder medications: This might reflect improved management strategies for urinary symptoms or a reduced tendency to attribute these symptoms solely to diuretic side effects.
Benzodiazepine to antidementia agents: This could suggest a move towards non-pharmacological interventions or choice treatments for cognitive decline, rather than attributing it to benzodiazepine use.
NSAIDs to antihypertensive medication: This finding is particularly interesting, as NSAIDs can sometimes exacerbate hypertension. A decrease in this sequence might indicate better blood pressure management or a reduced reliance on NSAIDs in patients with hypertension.
The study found no significant associations for urinary anticholinergic and antidementia agents, suggesting these medications are less likely to be involved in common prescribing cascades within this population.
the Challenge of Identifying and Preventing Prescribing Cascades
The study authors emphasized that identifying and confirming prescribing cascades remains a complex task. They noted that “prescribing cascades are challenging to identify and confirm and may require clinical process mapping to untangle the medication initiation sequence.” Further research is needed to explore potential effect modifications by factors such as age, sex, and individual medication characteristics to better understand and mitigate these patterns.
This research underscores the importance of vigilant medication review and a thorough understanding of potential drug-induced side effects, especially in older adults who are more susceptible to polypharmacy and its associated risks. Pharmacists play a crucial role in identifying and intervening in potential prescribing cascades,ensuring optimal patient outcomes and promoting safe medication use.
References:
- Doherty AS, Lund LC, Moriarty F, et al. Prescribing cascades among older community-dwelling adults: request of prescription sequence symmetry analysis to a national database in Ireland. Ann Fam Med*. 2025;23(4):315-324. doi:10.1370/afm.240383
- dreischulte T, Shahid F