Linaclotide 290microgram capsules

Linaclotide is a potent, highly selective agonist of guanylate cyclase-C (GC-C),[L47211] a soluble and single-membrane-spanning enzyme on the luminal surface of intestinal epithelial cells. GC-C regulates chloride secretion.[A260286] Linaclotide has a dual mode of action. Firstly, linaclotide and its active metabolite bind to transmembrane GC-C. Activation of GC-C results in an increase in both intracellular and extracellular concentrations of cyclic guanosine monophosphate (cGMP). Elevated intracellular cGMP activates the cGMP-dependent protein kinase II (PKG-II), which phosphorylates and activates the cystic fibrosis transmembrane conductance regulator (CFTR) ion channel expressed on the apical surface of intestinal epithelial cells.[A260276] CFTR activation promotes the secretion of chloride and bicarbonate ions and inhibits sodium absorption, resulting in increased intestinal fluid and accelerated GI transit.[A260271][A260276][L47211]

Secondly, linaclotide exerts anti-nociceptive effects by reducing visceral hypersensitivity. Increased levels of extracellular cGMP in submucosa inhibit colonic nociceptors, relieving intestinal pain.[A260271][A260276][A260281]