NSAIDs, Acetaminophen, and Paralytic Ileus
Acetaminophen is not a cause of paralytic ileus, as it does not share the same gastrointestinal risk profile as traditional NSAIDs. 1
Distinguishing Between NSAIDs and Acetaminophen
- Acetaminophen is classified as a non-NSAID analgesic with different pharmacological properties than true NSAIDs like ibuprofen 1
- Unlike NSAIDs, acetaminophen does not significantly inhibit prostaglandin synthesis in peripheral tissues, which explains its lack of anti-inflammatory effects and reduced GI toxicity 1
- NSAIDs work primarily through inhibition of cyclooxygenase (COX) enzymes, affecting prostaglandin synthesis throughout the body, including the gastrointestinal tract 1
Risk Factors for Paralytic Ileus
- Paralytic ileus is characterized by cessation of bowel motility and is a significant clinical concern in surgical patients 2
- Common causes of paralytic ileus include:
NSAIDs and Gastrointestinal Complications
- NSAIDs are associated with various gastrointestinal complications, with serious complications including bleeding, perforation, and obstruction 1
- The average relative risk of developing a serious GI complication is 3-5 times greater among NSAID users than non-users 1
- While NSAIDs can cause various GI complications, they are not typically considered a primary cause of paralytic ileus 4
- In fact, NSAIDs are sometimes used in postoperative care to reduce opioid requirements, which may indirectly help prevent ileus 4
Acetaminophen Safety Profile
- Acetaminophen has a favorable side-effect profile compared to NSAIDs regarding gastrointestinal effects 5
- In patients with a history of GI complications, acetaminophen is generally safer than NSAIDs 1
- Acetaminophen is often recommended as initial treatment for pain before considering NSAIDs, particularly in patients with GI risk factors 1
Clinical Implications and Management
- For patients at risk of paralytic ileus, review of analgesic prescription should include:
- Weaning of narcotics
- Substitution with regular paracetamol (acetaminophen)
- Use of NSAIDs if not contraindicated 3
- A study examining NSAIDs in colorectal surgery found they did not reduce time to gastrointestinal recovery but were associated with reduced postoperative opioid requirements 4
Important Caveats
- While high doses of acetaminophen may have some NSAID-like properties, these do not include the same risk for paralytic ileus 1
- The safety advantage of acetaminophen over NSAIDs is most pronounced in patients with risk factors for GI complications 1
- Patients taking multiple analgesics should be monitored for potential drug interactions and cumulative effects 1