Enfuvirtide is a linear 36-amino acid synthetic peptide that inhibits the fusion of HIV-1 with CD4 cells. Enfuvirtide works by disrupting the HIV-1 molecular machinery at the final stage of fusion with the target cell, preventing uninfected cells from becoming infected. Enfuvirtide interferes with the entry of HIV-1 into cells by inhibiting fusion of viral and cellular membranes. Enfuvirtide binds to the first heptad-repeat (HR1) in the gp41 subunit of the viral envelope glycoprotein and prevents the conformational changes required for the fusion of viral and cellular membranes. Enfuvirtide is indicated for the treatment of HIV-1 infection, in combination therapy with other antiretrovirals, in patients where all other treatments have failed. Common adverse drug reactions associated with enfuvirtide therapy include: injection site reactions (pain, hardening of skin, erythema, nodules, cysts, itch; experienced by nearly all patients, particularly in the first week), peripheral neuropathy, insomnia, depression, cough, dyspnoea, anorexia, arthralgia, infections (including bacterial pneumonia) and/or eosinophilia.

Secretin porcine stimulates pancreatic and gastric secretions to aid in the diagnosis of pancreatic exocrine dysfunction and the diagnosis of gastrinoma. Porcine Secretin for Injection administered intravenously stimulates gastrin release in patients with gastrinoma whereas only small changes in serum gastrin concentrations occur in healthy subjects and patients with peptic ulcer disease. The primary action of secretin is to stimulate pancreatic ductal cells to secrete pancreas fluid in large volumes that contain bicarbonate. Secretin is a hormone that is normally released from the duodenum upon exposure of the proximal intestinal lumen to gastric acid, fatty acids, and amino acids. Secretin is released from enterochromaffin cells in the intestinal mucosa. Secretin receptors have been identified in the pancreas, stomach, liver, colon, brain and other tissues. When secretin binds to secretin receptors on pancreatic duct cells it opens cystic fibrosis transmembrane conductance regulator (CFTR) channels, leading to secretion of bicarbonate-rich pancreatic fluid. Secretin may also work through vagal-vagal neural pathways since stimulation of the efferent vagus nerve stimulates bicarbonate secretion and atropine blocks secretin-stimulated pancreatic secretion.