Choosing Wisely – a look at prescribing cascades

choosing wisely

In the first of a six-part series, we expand on the PSA Choosing Wisely recommendations. This month: beware the prescribing cascade.

The decision to initiate a medication is a complex one1 and whilst prescribers strive to act in the best interest of the patient, we still see instances where medication are used to treat symptoms that are a result from adverse effects caused by another medication. This phenomenon is known as the prescribing cascade2 and is the focus of the PSA’s first of six recommendations in the Choosing Wisely Campaign.3

Recommendation 1. Do not initiate medications to treat symptoms, adverse events, or side effects (unless in an emergency) without determining if an existing therapy or lack of adherence is the cause, and whether a dosage reduction, discontinuation of a medication, or another treatment is warranted.

The choice to prescribe a medication is one of the most common therapeutic interventions.4 Although general practitioners prescribe the majority of medications used in Australia, there has been a steady growth of specialist and non-medical prescribers and an increased access to after-hours primary care.5

Whilst this provides much-needed improved access to care, one contributing factor may be that prescribers are making decisions in environments where only partial information may be available; thus, considering adverse drug reactions as the cause of the presenting symptom becomes slightly more difficult to elicit.

Technological and health system infrastructure such as My Health Record will hopefully lead to an improvement in this process. However, it is important to note that no single information source of information is complete and thus all healthcare providers involved with the patient need to be vigilant.

Prescribers in Australia need to demonstrate adherence to NPS prescribing competencies,1 and algorithms such as the BEGIN algorithm7 can help when initiating medicines. What can be overlooked is the emphasis on the question: ‘Is a medicine causing or exacerbating this effect?’ Enter the medicines expert, the pharmacist.

There are over 250,000 hospital admissions every year due to medication misadventure and 400,000 additional emergency visits.8 It is also estimated that 10% of patients visiting general practices will have had an adverse drug event in the previous six months.9

Those at higher risk of adverse drug reactions include2:

  1. Older adults;
  2. Those using multiple medicines;
  3. Women; and
  4. People using ‘high-risk medicines’, including cardiovascular drugs, NSAIDs, anticoagulants and antibiotics.

The key to preventing prescribing cascades lies in the avoidance and early detection of adverse drug reactions and an increased awareness and recognition of the potential for adverse reactions2 (see Box 1).

Box 1: Preventing a prescribing cascade – Adapted from Kalisch et al 2:

  • Wherever indicated, begin new medicines at low doses and tailor the dose to reduce the risk of adverse reactions
  • Consider the potential for any new symptoms to be caused by an adverse reaction or lack of adherence, particularly if a medicine has been recently started or the dose changed
  • Ask patients if they have experienced any new symptoms, particularly if a medicine has been recently started or the dose changed
  • Provide patients with information about possible adverse effects of medicines and what to do when adverse drug reactions occur, e.g. in the form of Consumer Medicines Information
  • The decision to prescribe a second medicine to counteract an adverse drug reaction from a first medicine should only occur after careful consideration, and where the benefits of continuing therapy with the first medicine outweigh the risks of additional adverse reactions from the second medicine
  • Have follow-up procedure in place particularly in the first month and then again within 4 months.

How can pharmacists play a role in wider adoption of the recommendation?

Pharmacists can practice vigilance around potential adverse effects in their patients. To demonstrate this, we have provided some example areas of practice. Whilst this is not an exhaustive list, it should 1) stimulate you into thinking how you can implement this recommendation in your practice, and 2) from a wider health system perspective, highlight the importance of embedding pharmacists in areas of the health system wherever there are medicines.

Dispensing medication

90% of adverse effects occur in the first 4 months, with 75% occurring in the first month.10 Having a systematic approach to medication management and identification of adverse effects, particularly within this time, may help to mitigate the risk of a prescribing cascade from the start.2

In the community pharmacy setting, automate reminders to discuss progress with patients, leveraging clinical recording software, particularly in the first 4 months of treatment. Tie in currently available services such as MedsChecks, Clinical Intervention recording, and Community Pharmacy Agreement Data Collection requirements to assist in having this focus.

Communication of potential adverse effects, what to expect, and most importantly, what to do about it if they do experience any issues is a key recommendation.

Symptom presentation

Pharmacists need to be vigilant upon presentation of a symptom-based request in the pharmacy, keeping front of mind a lens, ‘Is this symptom caused by a current medication?’

Whilst a large emphasis should be focusing on the most common adverse effects, this should not detract from the possibility of uncommon or rare adverse effects. Pharmacists should be thinking, ‘Is this a rare adverse effect I haven’t seen? Can I do something to mitigate this?’

Medication Review/ Reconciliation

Wherever medication reconciliation and review is undertaken including Medschecks, Home Medicine Reviews, hospital, transitional and aged care reviews, it is important to consider the sequence of when medicines were initiated and the role that each medicine may have in causation of symptoms and a prescribing cascade.

It is important to remember adverse effects may go on for a considerable period with patients either accepting that it is just as a result of their condition or are unaware there is a causal link to their medication.

Clear communication is warranted at all times particularly around reasons for changes to medications, to not exacerbate or reinstate a medication that was ceased due to adverse effect. Inclusion of adverse effects as well as allergies with every medication profile is warranted to assist in reducing this risk.

A systematic review on post-discharge medicine related harm suggests that between 19–51% of older adults have medication related harm in the 4–8 weeks post discharge.11

What if the prescribing cascade is necessary?

There are many scenarios where the prescribing cascade can be very beneficial to a patient, if not lifesaving. For example, it is often recommended to use proton pump inhibitors (PPIs) as gastro-protective agents in conjunction with gastric-irritants such as corticosteroids or non-steroidal anti-inflammatories (NSAID). Folic acid is recommended to be prescribed in conjunction with methotrexate, and laxatives are indicated for co-administration with opioids. In such instances where a prescribing cascade may be warranted, it is recommended to continually review the appropriateness of each medication prescribed.

Box 2: The recommendation

The prescribing cascade occurs when a new medicine is prescribed to ‘treat’ a side effect from another drug. The cascade often occurs in the mistaken belief that the side effect is a sign or symptom of a new condition requiring treatment. Other times, it can be a belief that it is more important to continue therapy with the original drug and prescribe another medicine to manage the side effects. Pharmacists and prescribers need to be aware that a new sign or symptom may potentially be a side effect of a current medicine.


The role of the pharmacist in every area of practice in integrating this first PSA Choosing Wisely recommendation will be the key to its success. Quality use of medicine interventions that involve addressing adherence, investigating if a medication is still necessary, assessing if a dose can be reduced, or identifying if another treatment is more suitable will be key to reducing the prescribing cascade, and ultimately, a much wiser choice of therapy.


  1. NPS: Better choices, Better health. Competencies required to prescribe medicines: putting quality use of medicines into practice. Sydney: National Prescribing Service Limited, 2012. At:
  2. Kalisch LM, Caughey GE, Roughead EE, Gilbert AL. The prescribing cascade. Aust Prescr 2011;34:162–6. At:
  4. Britt H, Miller GC, Henderson J, Bayram C, Harrison C, Valenti L, Pan Y, Charles J, Pollack AJ, Wong C, Gordon J. General practice activity in Australia 2015–16. General practice series no. 40. Sydney: Sydney University Press, 2016. At:
  5. Medicare Benefits Schedule GP and specialist attendances and expenditure in 2016–17. At:
  6. Nissen L, Kyle G, Cardiff L, Rosenthal M, Shah S. Pharmacist prescribing in Australia: An exploration of current pharmacist capabilities, required education and training to prescribe medicines and a process for moving forward 2017. At:
  7. Parekh, N., et al., A practical approach to the pharmacological management of hypertension in older people. Therapeutic Advances in Drug Safety, 2017. 8(4): p. 117-132. At:
  8. Pharmaceutical Society of Australia 2019. Medicine Safety: Take Care. Canberra: PSA. At:
  9. Miller GC, Britth HC, Valenti L. Adverse drug events in general practice patients in Australia. Med J Aust 2006;184:321- 4. At:
  10. Colebatch KA, Marley J, Doecke C, Miles H, Gilbert A. Evaluation of a patient event report monitoring system. Pharmacoepidemiol Drug Saf 2000;9:491-9. At:
  11. Parekh, N., et al. (2018). “Incidence of Medication-Related Harm in Older Adults After Hospital Discharge: A Systematic Review.” Journal of the American Geriatrics Society 66(9): 1812-1822. At: