From the FDA Drug Label
Gastric, biliary and pancreatic secretions are decreased by morphine. Morphine causes a reduction in motility and is associated with an increase in tone in the antrum of the stomach duodenum. ... Morphine can cause a marked increase in biliary tract pressure as a result of spasm of the sphincter of Oddi.
The effect of opioids on the Vater ampule (also known as the major duodenal papilla, where the pancreatic and bile ducts empty into the small intestine) in patients with pancreatitis is clinically significant. Opioids, such as morphine, can cause:
- Spasm of the sphincter of Oddi, leading to a marked increase in biliary tract pressure
- Decreased pancreatic secretions
- Reduced motility in the gastrointestinal tract These effects may exacerbate pancreatitis or worsen its symptoms. Therefore, caution should be exercised when using opioids in patients with pancreatitis, and alternative pain management strategies should be considered when possible 1.
From the Research
Opioids can have a clinically significant effect on the sphincter of Oddi (Vater ampulla) in patients with pancreatitis, but this concern should not prevent appropriate pain management. The most recent and highest quality study on this topic is from 2023, which found that opioids do not provide significant superiority over other medications and should be avoided due to their addictive nature 2. However, pain control remains essential in pancreatitis management. If opioids are needed, meperidine (Demerol) has traditionally been preferred at doses of 50-100mg every 3-4 hours as it theoretically causes less sphincter spasm, though this advantage is debated in recent literature. Fentanyl is another reasonable alternative at 25-100mcg IV every 1-2 hours as needed. For patients requiring ongoing pain control, hydromorphone 0.5-2mg IV every 3-4 hours may be used with close monitoring.
Some key points to consider when using opioids in patients with pancreatitis include:
- The risk of sphincter spasm should be considered alongside the patient's overall clinical condition, severity of pancreatitis, and pain management needs.
- Non-opioid analgesics should be tried first, and opioids should only be used when these are insufficient for pain control.
- The use of opioids should be closely monitored, and the patient should be regularly assessed for signs of addiction or overdose.
- Other studies have shown that opioids may be an appropriate choice in the treatment of acute pancreatitis pain, and may decrease the need for supplementary analgesia 3.
- However, the findings of these studies are limited by the lack of information to allow full appraisal of the risk of bias, the measurement of relevant outcomes, and the small numbers of participants and events covered by the trials.
In terms of specific medications, some studies have compared the use of different opioids in patients with pancreatitis. For example, one study found that transdermal fentanyl may be useful for treatment of some patients with painful chronic pancreatitis, but the dosage often has to be increased above that recommended by the manufacturer, and skin side effects often occur 4. Another study found that meperidine is the most commonly used rescue analgesic in patients with acute pancreatitis, and that metamizole and paracetamol are the most commonly used analgesics as initial pain treatment 5.
Overall, the use of opioids in patients with pancreatitis should be carefully considered, and the benefits and risks should be weighed on a case-by-case basis. The risk of sphincter spasm should be balanced against the harmful effects of uncontrolled pain, which can itself worsen outcomes through stress response, impaired respiratory function, and delayed mobility.