Linaclotide

Linaclotide is a guanylate cyclase-C (GC-C) agonist, a synthetic peptide composed of 14 amino acids. It is available in capsule form, with common dosages of 72 μg, 145 μg, and 290 μg. It is primarily used to treat irritable bowel syndrome with constipation (IBS-C) in adults. It is also indicated for the treatment of chronic idiopathic constipation (CIC).

Linaclotide binds to and activates the GC-C receptor in the intestines, increasing the intracellular levels of cyclic guanosine monophosphate (cGMP). Elevated cGMP activates the cystic fibrosis transmembrane conductance regulator (CFTR), promoting the secretion of chloride and bicarbonate ions into the intestinal lumen. This increases fluid in the intestinal cavity, enhances intestinal motility, and accelerates stool expulsion, thereby alleviating constipation symptoms. Additionally, elevated cGMP levels modulate the enteric nervous system, reducing visceral hypersensitivity and relieving symptoms such as abdominal pain and discomfort in patients with irritable bowel syndrome.