Ozempic (Semaglutide) and Gallbladder Disease: A Severity Grading Rubric

What the Ozempic label says about the gallbladder

Acute gallbladder disease is a warning in the Ozempic prescribing information: if cholelithiasis or cholecystitis are suspected, gallbladder studies are indicated [1]. That is the whole instruction. The warning carries no mild-to-severe scale and no threshold at which the drug is stopped for a biliary event [1].

Cholecystitis and cholecystectomy also appear among the label's postmarketing reports, where the label states that frequency cannot be estimated from voluntary reports [1].

Acute pancreatitis is a separate warning, and for it the label says to discontinue Ozempic if pancreatitis is suspected [1]. Maintenance dosing of Ozempic is 0.5, 1 or 2 mg once weekly [1].

The grading systems that exist for these conditions

For the gallbladder, the Tokyo Guidelines 2018 adopted the TG13 diagnostic criteria and severity grading for acute cholecystitis without modification [2]. Those authors report that the severity grading has been validated in numerous studies and is significantly associated with 30-day overall mortality, length of hospital stay, conversion rates to open surgery and medical costs [2].

For the pancreas, the revised Atlanta classification sorts acute pancreatitis into mild, moderate and severe. Mild disease has no organ failure or local or systemic complications and usually resolves in the first week; moderately severe disease involves transient organ failure, local complications or worsening of a coexisting condition; severe disease is persistent organ failure lasting more than 48 hours [3].

Both documents classify the conditions themselves, not the drug that may be involved [2][3].

How often gallbladder events occurred

SELECT enrolled 17,604 adults aged 45 or older with established cardiovascular disease and a BMI of 27 or more but no diabetes, with a mean follow-up of 39.8 months [5]. Gallbladder-related disorders occurred in 2.8% of those on semaglutide 2.4 mg versus 2.3% on placebo (p=0.04), driven mainly by cholelithiasis at 1.4% versus 1.1%; cholecystitis occurred in 0.6% of both groups [4].

Pooled analyses of the wider drug class are also available. A meta-analysis of 113 randomized GLP-1 receptor agonist trials in type 2 diabetes found cholelithiasis with a Mantel-Haenszel odds ratio of 1.30 (95% CI 1.01 to 1.68; P=0.041) [6]. A meta-analysis of 9 semaglutide trials, with 11,641 participants on semaglutide and 10,479 on placebo, all with overweight or obesity and no diabetes, found gallbladder disorders with an odds ratio of 1.26 (p=0.010) and cholelithiasis with an odds ratio of 2.06 (p=0.04) [8]. A 21-trial meta-analysis covering 99,599 patients treated with eight different GLP-1 receptor agonists reported a 26% increase in gallbladder disorders [9].

These trial results report how often gallbladder events occurred, not how severe those events were.

Weight loss, gallbladder emptying, and what remains unproven

Rapid weight loss increases the risk of gallstone formation [7]. Direct evidence on gallbladder contraction comes from a related drug. In a randomized, double-blind, two-period crossover study, healthy fasting volunteers received a single 10 microgram dose of exenatide or placebo 60 minutes before a cholecystokinin infusion. Maximal gallbladder ejection fraction was 28.79% with exenatide versus 46.13% with placebo (least-squares mean difference -17.34%; 95% CI -30.54 to -4.13), while gallbladder volume and ejection fraction before the infusion were unaffected [10].

Exenatide is not semaglutide, and that study used one dose in healthy volunteers. The finding does not establish the mechanism of gallbladder events with semaglutide [10].

Grading a real case

The Ozempic label says gallbladder studies are indicated if cholelithiasis or cholecystitis are suspected [1]. For diagnosed acute cholecystitis or acute pancreatitis, severity is graded with the Tokyo Guidelines or the revised Atlanta classification respectively [2][3]. Ozempic has no biliary severity scale of its own [1].