Exenetide is a functional analog of the human incretin glucagon-like peptide-1(GLP-1). Incretin enhance glucose-dependent insulin secretion and exhibit other antihyperglycemic actions following their release into the circulation from the gut. The GLP-1 system increases insulin secretion only in the presence of elevated plasma glucose levels, avoiding inappropriately high insulin levels during fasting. The drug also moderates peak serum glucagon levels during hyperglycemic periods following meals, but does not interfere with glucagon release in response to hypoglycemia. Secondary effects to drug administration reduces the rate of gastric emptying and decreases food intake, mitigating the potential severity of hyperglycemic events after meals.
Reference: Tripathi KD; Essentials of Clinical Pharmacology; Jaypee Brothers Medical Publishers; seventh edition; Page no: 270