Which opioids cause sphincter of Oddi spasm?

Which Opioids Cause Sphincter of Oddi Spasm?

All opioid agonists cause sphincter of Oddi spasm through activation of mu (μ) opioid receptors in the biliary tract, resulting in increased intrabiliary pressure and spasm of the sphincter of Oddi. 1

Mechanism of Action

Opioids exert their biliary effects primarily through mu receptor activation, which results in:

• Spasm of the sphincter of Oddi
• Increased intrabiliary pressure
• Tonic non-propulsive contractions 1, 2

Specific Opioids and Their Effects

High-Risk Opioids (Strongest Evidence of Spasm)

Morphine is the most extensively documented opioid causing sphincter of Oddi spasm:

• Produces the largest elevation in biliary pressure compared to other opioids 3, 4
• Increases basal pressure of Oddi's sphincter (BPOS), amplitude of phasic contractions (SOCA), and frequency of phasic contractions (SOF) 3
• Can cause dramatic increases in hepatic enzymes (transaminases >1,000 U/L) due to high biliary pressure and hepatocellular necrosis 5
• Effects are dose-dependent: higher doses (5-10 μg/kg) significantly increase sphincter pressure 6

Fentanyl demonstrates dose-dependent effects:

• At doses of 5 and 10 μg/kg: significantly increases sphincter pressure 6
• Paradoxically, at very low doses (1 μg/kg): may actually relax the sphincter 6
• Periarticular morphine absorption can cause systemic sphincter of Oddi spasm 7

Ap-237 (synthetic opioid):

• Increases BPOS, SOF, and SOCA similar to morphine 3

Moderate-Risk Opioids

Meperidine (Pethidine):

• Contrary to traditional teaching, meperidine does affect the sphincter of Oddi 4
• All narcotics increase sphincter of Oddi phasic wave frequency and interfere with peristalsis 4
• However, direct manometry studies show no apparent change in sphincter pressure with regular doses 3
• The historical preference for meperidine over morphine in pancreatitis is not evidence-based 4

Lower-Risk Opioids

Tramadol shows an inhibitory effect:

• Decreases BPOS from 7.01±5.50 mmHg to 2.87±2.78 mmHg at 10 minutes 3
• Decreases amplitude of phasic contractions 3
• May be a safer alternative when sphincter of Oddi spasm is a concern

Special Considerations

Mixed Opioid Receptor Drugs

Eluxadoline (μ-opioid and κ-opioid receptor agonist, δ-opioid receptor antagonist):

• Contraindicated in patients with prior sphincter of Oddi problems or cholecystectomy 8, 9, 8, 10, 8
• Can cause pancreatitis and sphincter of Oddi spasm (0.5% incidence in trials) 10, 8
• Also contraindicated in alcohol dependence, pancreatitis, or severe liver impairment 8, 9, 8

Clinical Manifestations

Patients may present with:

• Severe epigastric colicky pain radiating to the back
• Dramatic elevation in transaminases (can exceed 1,000 U/L)
• Pain refractory to conventional opioid analgesia
• Bradycardia in severe cases 7

Treatment of Opioid-Induced Sphincter Spasm

Butylhyoscine (hyoscine butylbromide):

• Effectively antagonizes the increased sphincter pressure caused by fentanyl 6
• Decreases sphincter pressure, frequency, amplitude, and duration of waves 6

Glucagon:

• Effective treatment for acute sphincter of Oddi spasm 7

Clinical Implications

For Acute Pancreatitis

• No evidence supports avoiding morphine in acute pancreatitis 4
• No outcome-based studies comparing morphine versus meperidine exist in pancreatitis patients 4
• Morphine may offer longer pain relief with less seizure risk than meperidine 4

For Patients at Risk

• Avoid all opioid agonists in patients with known sphincter of Oddi dysfunction
• Consider tramadol as a potentially safer alternative given its inhibitory effects 3
• Never use eluxadoline in patients with prior sphincter of Oddi problems or post-cholecystectomy 8, 9, 10

Postoperative Considerations

Higher doses of postoperative narcotics increase clinically significant pancreatic fistula rates in distal pancreatectomy patients, reinforcing the functional role of the sphincter of Oddi 11