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The following is a summary of “No Effect of Methylnaltrexone on Acute Pancreatitis Severity: A Multicenter Randomized Controlled Trial,” published in the November 2024 issue of Gastroenterology by Knoph et al.  

Opioids, commonly used to treat pain in acute pancreatitis (AP), may worsen the condition by affecting gastrointestinal and immune functions. Methylnaltrexone, a µ-opioid receptor antagonist, could mitigate these effects without altering pain relief.  

Researchers conducted a prospective study to evaluate the effect of methylnaltrexone on the severity of acute pancreatitis.  

They conducted a double-blind, randomized, placebo-controlled trial at 4 centers in Denmark, 105 adult patients with AP and systemic inflammatory response syndrome (SIRS) were randomly assigned to receive 5 days of continuous intravenous methylnaltrexone (0.15 mg/kg/d) or placebo, alongside standard care. The primary outcome was the Pancreatitis Activity Scoring System (PASS) score after 48 hours of treatment. Secondary outcomes included pain severity, opioid use, disease severity, and mortality.  

The results showed that after 48 hours, the PASS score was 134.3 in the methylnaltrexone group and 130.5 in the placebo group (difference 3.8, 95% CI −40.1 to 47.6; P=0.87). No significant differences in pain severity (0.0, 95% CI −0.8 to 0.9; P=0.94), pain interference (−0.3, 95% CI −1.4 to 0.8; P=0.55), or morphine equivalent doses (6.5 mg, 95% CI −2.1 to 15.2; P=0.14). Methylnaltrexone did not affect the risk of severe disease (8%, 95% CI −11 to 28; P=0.38) or mortality (6%, 95% CI −1 to 12; P=0.11). The medication was well tolerated.  

They concluded that methylnaltrexone did not reduce the severity of AP compared to placebo.  

Source: journals.lww.com/ajg/fulltext/2024/11000/no_effect_of_methylnaltrexone_on_acute.29.aspx