Delayed Gastric Emptying
Abnormally slow movement of food from the stomach into the small intestine. While therapeutic slowing of gastric emptying is a desired effect of GLP-1 receptor agonists, clinically significant delayed emptying (gastroparesis) is a potential adverse effect under ongoing regulatory investigation.
Technical Context
Clinical assessment: scintigraphic gastric emptying study (gold standard — patient eats radiolabelled meal, gamma camera tracks gastric retention at 1, 2, 3, 4 hours; >10% retention at 4 hours = delayed), wireless motility capsule (SmartPill — measures pH, pressure, temperature throughout GI transit), and 13C-breath test (non-radioactive, measures gastric emptying of 13C-labelled substrate). GLP-1 RA-associated gastric emptying concerns include: impact on oral medication absorption (drugs requiring rapid absorption may have delayed Tmax and reduced Cmax — relevant for time-sensitive medications like oral contraceptives, antibiotics), anaesthesia risk (aspiration of gastric contents — guidelines suggest considering gastric emptying delay for patients on GLP-1 RAs undergoing general anaesthesia, though the degree of risk and appropriate management remain debated), and the gastroparesis safety signal (rare cases of severe, persistent delayed emptying beyond the expected pharmacological effect).