A 62-year-old woman presents to the emergency department with hematemesis for the past 2 hours. She reports generalized itching and fatigue for the past 4 months. She endorses lightheadedness and denies sore throat. She has a past medical history of rheumatoid arthritis and primary biliary cholangitis. Vital signs are temperature 100.0° F (37.8° C), blood pressure 100/60 mmHg, pulse 110 beats/minute, and respirations 20/minute. Physical examination reveals tachycardia, scleral icterus, and hepatomegaly. The patient’s skin is noted to be yellowish, clammy, and with erythematous scratch marks. Lab studies show a hemoglobin of 8.1 g/dL, total bilirubin 2.9 mg/dL, direct bilirubin 2.0 mg/dL, serum alanine aminotransferase (ALT) of 90 U/L, serum aspartate aminotransferase (AST) of 110 U/L, serum alkaline phosphatase 180 IU/L, and an increased urine conjugated bilirubin. Endoscopy is performed and reveals esophageal varices that appear to have bled recently. The patient is treated with octreotide.
Which of the following best describes the mechanism by which octreotide treats the current diagnosis?
D) Inhibits splanchnic vasodilation through suppressing secretion of hormones
Octreotide is a long-acting somatostatin analog used for acute variceal bleeds and varices at high risk for bleeding. Octreotide is also used in the treatment of other conditions such as acromegaly, vasoactive intestinal peptide-secreting tumor (VIPoma), and carcinoid tumor.
Answer choice A: Agonist at opioid receptor, is incorrect. This describes the mechanism of action of loperamide and diphenoxylate. These opioid agonists are used to decrease gut motility as anti-diarrheals.
Answer choice B: Depolarizing neuromuscular blocker, is incorrect. This describes the mechanism of action of succinylcholine. Succinylcholine is a nicotinic acetylcholine receptor agonist and depolarizing neuromuscular blocker that is used in tracheal intubation and mechanical ventilation.
Answer choice C: Increases cardiac inotropy through PDE-3 inhibition, is incorrect. This describes the mechanism of milrinone. Milrinone inhibits PDE-3 to increase cardiac inotropy and chronotropy to treat acute decompensated heart failure with cardiogenic shock.
Answer choice E: Permits mucosal protection of ulceration, is incorrect. This is the mechanism of action of bismuth and sucralfate. These medications are mainly used to promote gastric ulcer healing.
Key Learning Point
Esophageal varices result secondary to portal hypertension and cirrhosis, and they can present with bleeding which presents with painless hematemesis. This patient has primary biliary cholangitis which can cause cirrhosis and lead to the development of esophageal varices. The patient has signs and symptoms of cirrhosis including pruritus, obstructive jaundice, and elevated total bilirubin, elevated direct bilirubin, and elevated liver transferases. An elevated alkaline phosphatase is almost always present in primary biliary cholangitis. Octreotide is a somatostatin analog that is used in acute variceal bleeds by inhibiting splanchnic vasodilatory hormones. Through this same mechanism it is also used in the treatment of acromegaly, VIPoma, and carcinoid tumors.
