Acetaminophen in Osteoarthritis
When I was in school, acetaminophen was considered the go agent for the management of osteoarthritis pain. While acetaminophen in osteoarthritis is still possibly a 2nd or 3rd line consideration, more evidence has come to light over the years that maybe it really isn’t that helpful. This review from a few years back demonstrated that the efficacy of acetaminophen is at least questionable in osteoarthritis.
So where does that leave us? For those that primarily practice in geriatrics, should we use more NSAIDs? Oral NSAIDs have a ton of potential issues in this patient population. They include.
- NSAIDs can cause GI bleeding without any additional help. When working with the elderly we often run into the complication of polypharmacy. Many elderly patients are on anticoagulant and antiplatelet medications which can significantly increase the risk of a GI Bleed.
- When you’ve seen numerous hospitalizations due to NSAIDs, I can’t help but wonder why these medications are over the counter? Concern #2 is that many patients equate over the counter = safe. Poorly monitored use of NSAIDs can lead to bad outcomes and poor monitoring is more likely if patients are self treating without speaking to a pharmacist or other qualified healthcare professional.
- NSAIDs can exacerbate kidney disease which is common problem in the elderly. Many elderly patients are already necessarily on drugs for CHF/hypertension like diuretics and ACE Inhibitors worsening the risk for acute renal failure. If you are a student reading this, remember the afferent/efferent rant that I suspect one of your professors taught you. Clinically, it matters.
- With the use of NSAIDs, there is a US boxed warning. NSAIDs are associated with an increase in the risk of cardiovascular thrombotic events (like MI and stroke).
- I mentioned the risk of acute kidney injury above due to concomitant use with ACE/diuretics etc. Another disease state that can be significantly exacerbated by NSAIDs is CHF. NSAIDs can contribute to fluid retention leading to increasing symptoms of CHF.
Given the risks of NSAIDs (oral), and the likely ineffectiveness of acetaminophen, I’m starting to focus more and more on topical agents. Topical NSAIDs, like diclofenac, and a medication like capsaicin could be a potentially beneficial and very safe option in many circumstances. We obviously have to look at the location of the osteoarthritis pain. If OA is prevalent in many areas of the body, this gets more challenging.
Duloxetine has been a consideration that has gained some steam in those that can’t take oral NSAIDs. Here is an article that demonstrates the potential benefit of duloxetine in osteoarthritis. Avoiding opioids is ideal in osteoarthritis and isn’t something I would recommend on a regular basis.
Just because acetaminophen in osteoarthritis has lost some luster over time, it doesn’t mean we can’t use medications to help patients manage their pain. Identify if topical agents are an option to avoid systemic NSAID use and consider duloxetine in patients who need a systemic agent.
As a pharmacist, it is easy to focus on medications. Lastly, I want to point out that there are numerous non-pharmacologic interventions that have been shown to have some efficacy. The most evidence lies with exercise.