Irish Study Identifies Five Medication Cascades Risking Older Adults' Health

A newly published study in the *Annals of Family Medicine* has unveiled significant findings regarding prescribing cascades among older adults in Ireland, highlighting potential risks associated with polypharmacy. Conducted by researchers at University College Cork, the study analyzed national prescription data for 533,464 community-dwelling adults aged 65 and older, covering prescriptions dispensed from 2017 to 2020. Funded by the Health Research Board of Ireland, this research was aimed at understanding how certain medications can lead to additional prescriptions, often resulting in unnecessary health risks.

The term 'prescribing cascade' refers to a scenario where side effects from one medication prompt the prescription of another, potentially leading to a cycle of additional medications. The researchers identified five clinically relevant prescribing cascades, with the most prominent being the transition from calcium channel blockers to diuretics. Approximately 2.6% of patients starting on a calcium channel blocker went on to receive a diuretic prescription within a year, equating to one additional diuretic prescription for every 78 patients treated.

Dr. Ann Sinéad Doherty, the lead author of the study and a researcher at University College Cork, emphasized the significance of recognizing adverse drug reactions. "An increasing number of medications in older people is strongly associated with an increased risk of medication-related harm and serious adverse drug reactions," she stated. The study's findings underscore the need for clinicians to consider adverse drug reactions when diagnosing new symptoms in primary care settings.

The analysis revealed four other notable prescribing cascades: 1. **Alpha-1-receptor blockers to vestibular sedatives**: Approximately 3% of users of alpha-1 blockers, commonly prescribed for benign prostatic hyperplasia, proceeded to receive a vestibular sedative, translating to one additional sedative prescription for every 85 patients. 2. **SSRIs/SNRIs leading to sleep agents**: About 2.5% of those prescribed selective serotonin reuptake inhibitors (SSRIs) or selective norepinephrine reuptake inhibitors (SNRIs) for depression were subsequently prescribed sleep agents, resulting in an additional prescription for one in every 115 patients. 3. **Benzodiazepines to antipsychotics**: This cascade appeared in 3.2% of benzodiazepine initiators, with one additional antipsychotic prescription for every 242 patients. 4. **Antipsychotics to antiparkinsonian agents**: Approximately 0.4% of antipsychotic users received an antiparkinsonian agent prescription, amounting to one additional prescription for every 1,644 patients.

The study emphasizes that while prescribing cascades can occur unintentionally, they often reflect a failure to recognize the adverse effects of medications. It also points out that physicians sometimes avoid prescribing combinations that are known to have negative associations, indicating a level of awareness in the medical community.

Dr. Lars Christian Lund, a co-author of the study and an expert in clinical pharmacology, argues that these findings call for a careful evaluation of medication regimens in older adults. "Identifying prescribing cascades and deprescribing when appropriate offers potential to reduce pill counts and associated treatment burdens for patients," Dr. Lund commented.

The implications of this study are far-reaching. As the population of older adults continues to grow, healthcare systems must prioritize strategies to mitigate the risks associated with polypharmacy. The findings of this research not only highlight the critical need for heightened awareness among healthcare professionals but also advocate for patient-centered approaches in managing medications for older adults.

In conclusion, as polypharmacy becomes increasingly prevalent among older populations, understanding the intricacies of prescribing cascades is essential for improving patient safety and health outcomes. Future studies could expand on these findings by exploring the long-term consequences of these prescribing practices and the effectiveness of interventions aimed at reducing unnecessary prescriptions.