All about prescribing cascades in long-term care

What is a prescribing cascade?

A prescribing cascade begins when a medicine causes an adverse drug reaction that is mistaken for a new medical condition, leading to the prescription of another, often unnecessary, medicine. Sounds simple, but particularly in older adults, this can snowball quickly, leading to more medicines being given to treat a cascade of events from a previously prescribed medicine.

Older adults accessing long-term care either at home with home care packages or at residential aged care facilities, especially those with multiple chronic conditions and complex care needs, are particularly vulnerable to this cycle. The impact of prescribing cascades on medication-related quality of care is significant, as unnecessary medicines can lead to adverse outcomes and added costs.

One well-known example involves the use of calcium channel blockers like amlodipine for hypertension, which can cause lower extremity swelling (ankle oedema). If this swelling is misinterpreted as a new condition, a diuretic like furosemide might be added unnecessarily, worsening the patient’s condition without addressing the real cause.

Another example from the literature, published in the journal Geriatrics & Gerontology International, highlights a series of prescribing cascades following the initiation of an angiotensin converting enzyme – ACE – inhibitor. An older adult who started an ACE inhibitor, enalapril, to manage their hypertension developed a non-productive cough, an adverse drug event well-documented with ACE inhibitors.

However, instead of recognising the cough as a side effect of the enalapril, a cough suppressant syrup containing guaifenesin and codeine was prescribed to treat the cough. The codeine caused lethargy and the cough persisted, which was then mistaken for the early stages of pneumonia. As a result, an antibiotic levofloxacin was prescribed to treat the presumed pneumonia, which then led to an antibiotic-induced diarrhoea. Diarrhoea and dehydration triggered delirium, finally led the patient to be hospitalised.

Prescribing cascades are not limited to prescription medicines. They can involve over-the-counter medicines or supplements, medical devices or procedures, for example pacemaker device insertion following medication-induced bradycardia, which could have been avoided by reducing dose or substituting with a safer alternative.

How common are they among aged care residents?

Prescribing cascades have been recognised for nearly 30 years, yet they remain common in long-term care, contributing to polypharmacy, inappropriate prescribing and medication-related harm. They can be a marker of poor medication-related quality of care. Older adults receiving long-term care are often on multiple medicines – 10 on average – have complex medicine regimens, and as they transition between care settings including hospital, rehabilitation, home care and residential aged care facilities, adverse drug reactions could be misinterpreted for new conditions.

Evidence shows that over 95 per cent of aged care residents have at least one medication-related problem, and one in six of these are linked to adverse drug reactions, which often trigger prescribing cascades.

Identifying prescribing cascades is key to improving medication safety in long-term care

What can happen as a result?

The consequences of a prescribing cascade can be significant, from mild side effects to severe medication-related harms like falls and major injury, delirium or hospital admissions. These not only affect the individual’s quality of life but also place added strain on health and aged care providers and increase costs due to hospitalisations and ongoing management of medication-induced conditions.

How can you detect a prescribing cascade?

Identifying prescribing cascades is key to improving medication safety in long-term care. When new symptoms arise, it is important to ask: “Could this be an adverse drug reaction of a current medicine?” Maintaining a high index of suspicion for new signs or symptoms is critical to identify and interrupt prescribing cascades.

Tools like Canada’s “ThinkCascades” list of common cascades can help clinicians identify potential cascades by systematically looking at common medicines and their associated side effects. Comprehensive medication management review, especially after transitions of care or when new symptoms arise, ensure that providers are not missing opportunities to catch adverse drug reaction early, before a prescribing cascade starts.

How can you prevent prescribing cascades?

Preventing prescribing cascades improves care quality and also supports the 10th National Health Priority Area: Quality Use of Medicines and Medicines Safety. Australia’s Choosing Wisely initiative advises prescribers to recognise and stop prescribing cascades. Prevention begins with judicious prescribing and regular reviews of a resident’s medicines to ensure no unnecessary medicines are added – in particular avoiding high-risk medicines for older adults.

Clinical practice guidelines and tools, such as the American Geriatrics Society Beers Criteria, Screening Tool of Older Persons’ Prescriptions – known as STOPP – and other explicit criteria to identify potentially inappropriate prescribing, help clinicians make safer choices for older adults.

If a prescribing cascade has already started, deprescribing – systematically reducing dose or stopping medicines – can improve care quality and reduce harm. Technology, such as clinical decision support tools, can also alert clinicians to the occurrence of a prescribing cascade during prescribing decisions. Recognising and stopping prescribing cascades are essential yet often overlooked steps for optimising prescribing practices and improving medication-related quality of care in long-term care settings.

Dr Tesfahun Eshetie is a research fellow with the Registry of Senior Australians at the South Australian Health and Medical Research Institute and expert in drug safety in the elderly

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