Pharmacodynamics
Liraglutide is a synthetically produced analog of the endogenous "glucagon-like-peptide-1" (GLP-1). The major advantage of this active ingredient lies in its modified structure, as it has a greatly extended retention time in the blood due to the addition of a fatty acid and a slight modification of the amino acid sequence. The endogenously occurring GLP-1, on the other hand, is broken down in the body by the body's own enzymes in the intestine after only about 1-2 minutes.
Like GLP-1, liraglutide binds to the glucagon-like peptide-1 receptor. Binding to the receptor and the resulting increase in cyclic AMP stimulates the glucose-dependent release of insulin, inhibits the glucose-dependent release of glucagon, and slows gastric emptying. Through these mechanisms, post-meal blood glucose levels are kept low.
Pharmacokinetics
The bioavailability of liraglutide after subcutaneous injection is approximately 55% and the maximum plasma concentration is reached after approximately 11 hours. Liraglutide is present in the blood more than 98% bound to serum albumin. Due to its altered structure, liraglutide is degraded and metabolized much more slowly by the enzyme dipeptidyl peptidase-4 (DPP4), which is why its plasma half-life is about 13 hours.