A study published in BMJ has found that prescribing medications such as blood pressure drugs, statins, an Alzheimer’s drug and iron supplements can lead to 'prescribing cascades' to combat adverse reactions. The research involved 2,297,942 people to investigate the impacts of prescriptions.
What is a prescribing cascade?
A prescribing cascade occurs when a drug is prescribed to a patient, an unrecognised adverse reaction develops, and a second drug is prescribed to manage that reaction under the mistaken impression that a new medical condition has appeared.
The research, led by Dr Paula Rochon, Director of Research at the Weston and O’Born Centre for Mature Women’s Health at Sinai Health in Toronto, has revealed that certain drug combinations are a common but little-known contributor to drug harm at the population level and add unnecessary costs to the healthcare system.
Common examples and vulnerable groups
A potentially inappropriate prescribing cascade (PIPC) happens when a medication’s side effect gets mistaken for a new health problem, leading to another prescription that may not have been needed in the first place. One common example flagged in the study involves non-steroidal anti-inflammatory drugs (NSAIDs). Commonly prescribed for pain, these drugs are associated with a rise in blood pressure, which can lead to a new prescription for high blood pressure, rather than a second look at the original pain medication. Older adults are especially vulnerable to this pattern because they’re more likely to be on multiple medications at once, due to having multiple conditions, making it harder for both patients and clinicians to trace a new symptom back to an existing drug.
Dr Rochon said: “These sequences of events are common but often missed in clinical practice. Knowing what medications, you are taking, when they were started and for what indication is important in order to identify possible prescribing cascades that may be problematic”
Study findings and impact on mature women
The researchers examined each PIPC against three factors: how common the initial drug was in the population, how often it was followed by the second drug, and how strong the link was between the two. That analysis allowed them to pinpoint the 24 potentially inappropriate prescribing cascades most commonly seen in the population and with a potential to cause harm.
Dr Rochon explained “Our concern is that so often these conversations between the health care prescriber and the patient are being missed, so people don’t recognize the sequences of events and that they are connected to one another.”
The work also carries a particular weight for mature women, as they tend to live with more chronic conditions than men over their lifetime. Mature women are prescribed more drug therapies, and experience more adverse drug events. By being on multiple medications at once, they are more exposed to the risk that a drug’s side effect gets mistaken for a new diagnosis rather than traced back to its source.
Potential next steps for health professionals
The first involves technology. Automated clinical decision support tools could flag a prescribing cascade in real time and prompt a second look before a new prescription is added. This information could be leveraged in one of several automated ways to help clinicians be aware of these potentially inappropriate prescribing cascades at the point of care.
Next is optimising the role of pharmacists as part of the care team and more directly integrating them into the prescribing process alongside physicians. Their expertise can help identify these potentially inappropriate prescribing cascades for further evaluation.
Before adding a new drug to manage a new symptom in an older adult, clinicians are advised to ask: Is the new symptom a potential side effect of an existing medication? Is a safer alternative or lower dose available for the initial drug? Is the initial drug truly necessary, or can it be deprescribed?
