Polypharmacy is technically defined as taking five or more medications on a daily basis. Polypharmacy is increasingly becoming the norm among adults, due to several factors (an aging population, increasing numbers of medical problems, and increasingly complex regimens available to treat chronic disorders such as heart failure). Indeed, the term “polypharmacy” is arguably antiquated now that it's so common, so perhaps the term “hyperpolypharmacy” (>10 medications/day) would be more helpful.
What happens when a patient on numerous home medications gets admitted to the ICU? We add a lot more medications. The result may be a dizzying medication list with dozens of medications.
This post will explore seven reasons that when in doubt about whether to continue home medications, our default position should be to hold them.
reduction in drug-drug pharmacokinetic interactions
Pharmacokinetic interactions involve alterations in drug metabolism, which may cause one or both interacting medications to have unexpected drug levels. As the number of prescriptions increases, it's increasingly likely that drug-drug interactions will occur. One example is that pharmacokinetic interactions may be problematic if a patient needs to be emergently started on medications that interact with the P450 system (e.g., an azole antifungal medication).
reduction in drug-drug pharmacodynamic interactions
Pharmacodynamic interactions often involve drugs with similar physiological effects, which may have an excessive clinical effect when taken together. With an increasing number of prescriptions, such interactions are increasingly likely. One classic example here is serotonin syndrome: perhaps the patient is on one or two serotonergic medications prior to admission. After admission to the ICU additional serotonergic medications are added (e.g., ondansetron and fentanyl), precipitating serotonin syndrome.
avoiding drug accumulation
Patients in the ICU frequently have impaired drug clearance due to renal and/or hepatic insufficiency. This necessitates redosing all medications. In a busy ICU, it's easy to overlook the redosing of home medications, especially if they aren't familiar to the ICU practitioners.
chronic medications offer risks > benefits
Many chronic prescriptions are administered with preventative intent, to reduce the likelihood of long-term health risks. An ICU stay isn't long enough for such medications to cause measurable benefit for the patient. In the context of critical illness, potential toxicities will often outweigh any potential benefits of long-term preventative therapies.
patients are being closely monitored
The ICU may represent an ideal opportunity for deprescription. If the patient does respond adversely to the removal of a medication, it may be immediately reinstituted.
reduction in medication errors
Medication errors may vary from frank mistakes (e.g., wrong medication) to less egregious yet still problematic errors (e.g., failing to hold an antihypertensive medication in the context of hypotension).
As patients are on greater numbers of medications, errors are increasingly likely to occur. Imagine a nurse managing two ICU patients. If both patients are on 25 medications, then the nurse is responsible for administering 50 medications/day – a task which is difficult to do in a thoughtful manner. If both patients are on 10 medications each, there is more likelihood that the nurse will have time to slow down and think about whether medications should be held based on changes in the patient's condition.
Similarly, in a 20-bed ICU, if every patient is on 25 medications then that's a total of 500 prescriptions that require management by the ICU team. Safely prescribing 500 medications to a cohort of critically ill patients without causing harm can be challenging.
reduction in costs (including nurse and respiratory therapist time)
We're often conscious of the costs of medications that we add to the patient's prescription list. However, chronic therapies that the patient has been on tend to run underneath the radar. Costs of unnecessary medications include the cost of the drug itself, as well as work expended by nurses and respiratory therapists to administer the drug (yeah, I'm looking at you albuterol). These aggregated costs can be substantial.
- As our patients are increasingly complex, the rates of outpatient polypharmacy (5 or more medications/day) and hyperpolypharmacy (>10 medications/day) are rising.
- In the context of critical illness, we will generally initiate several more medications. When combined with the patient's home medications, this can easily create a dangerously confusing and extensive list of medications.
- When in doubt about whether to continue a home medication, the default position should be to err towards discontinuation (primum non nocere). This may help reduce several problems in ICU regarding drug-drug interactions, medication accumulation, medication errors, and medication cost.
Image credit: Photo by Myriam Zilles on Unsplash
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Thanks a lot I am agree with you perhapse Using AI at ICU can be a solution to reduce hyperpolypharmacy
Hi Josh, I appreciate this post and my general stance has been to not order most home medications on ICU admission, but I am always very uncertain about drugs like baclofen, which can have significant withdrawal effects, or other meds that we are told in the outpatient setting to taper patents off of rather than stop abruptly, including SSRIs and gabapentin. Do you know of any review articles or other resources I could read to get a better handle on this? Really, I think this could be made into an entire chapter in the IBCC!