The dreaded “Prescribing Cascade”... Have you heard of this?
Let's delve into it, shall we?
A prescribing cascade occurs when the side effect of a drug is misinterpreted as a new medical condition, which leads to the addition of another, potentially avoidable, medication.
This leads to polypharmacy and further increases the risk of adverse drug events.
Let’s consider a patient, we can call her Mrs. Smith.
Mrs. Smith was prescribed ramipril, an angiotensin-converting enzyme inhibitor (or ACE inhibitor), to help treat her blood pressure. Within a month her blood pressure was in range - Yay!
About 6 months later, Mrs. Smith developed a dry, tickly cough that just wouldn’t go away. She was prescribed hydrocodone, an opioid cough suppressant. This led to drowsiness, interfering with her ability to work and drive, as well as constipation. Well, that’s not ideal!
Guess what?! The ACE inhibitor was the culprit for the dry cough. This side effect can occur months or even years after it is started. If that was identified in the first place, it could have easily been stopped and changed for another blood pressure reducing medicine. This would have avoided the new drug which caused Mrs. Smith even more side effects.
This is just one example of prescribing cascades, but there are many:
Calcium channel blockers (CCBs), like amlodipine, to treat heart conditions → ankle edema → diuretic (in one study, this cascade occurred in 9.5% of older adults who were prescribed a CCB!)
NSAID (non-steroidal antiinflammatory medication), like ibuprofen, used for arthritis → increase in blood pressure → drug for hypertension
Thiazide diuretic, like hydrochlorothiazide, for high blood pressure → high uric acid levels in the blood, which causes gout → gout treatment
Cholinesterase inhibitor, like donepezil, to treat dementia → urinary incontinence → incontinence treatment (some of which can make cognitive impairment worse!)
Opioids, like oxycodone, used for pain → constipation → laxative
Antidepressant like bupropion → insomnia → sleeping pill → blurry vision, dry mouth, brain fog
Bisphosphonate, like alendronate, used for osteoporosis → reflux, stomach ache → antacid
See how easy it is for these to happen?
You should know that prescribing cascades are PREVENTABLE. Cascades can be identified and inappropriate polypharmacy can be avoided. Once we discover that a drug is causing a side effect, we can consider stopping or deprescribing and look at alternatives for the first medication if needed.
Here’s what you can do to avoid a prescribing cascade:
Stay informed and educate yourself about possible side effects.
Don’t forget your non-prescription (OTC) medications and supplements when talking to your healthcare providers. These be culprits of prescribing cascades too!
Have a Pharmacist Coach review your regimen to identify and fix prescribing cascades.
Have you come across a prescribing cascade? I would love to hear!