Digestive System Pharmacology

A comprehensive set of vocabulary flashcards covering digestive system pharmacology, including medications for H. pylori, PUD, GERD, nausea, constipation, IBS, and biliary/pancreatic disorders.

Helicobacter Pylori (H-pylori)

A gram-negative bacillus that colonizes the stomach in approximately 40% of the world's population and increases the risk of gastritis, PUD, gastric adenocarcinomas, and mucosa-associated lymphoid tissue B-cell lymphoma.

H-pylori Eradication Therapy

A recommended combination of 2-3 antibiotics plus a proton pump inhibitor taken for 10-14 days to clear colonies and prevent resistance.

Histamine2-receptor Antagonists (H2-blockers)

Oral and/or IV medications, such as Cimetidine (Tagamet) and Famotidine (Pepcid or Zantac), that suppress gastric acid by blocking H2 receptors to treat GERD, ulcers, and heartburn.

Cimetidine (Tagamet) Adverse Effects

Unique side effects including blocked androgen receptors leading to decreased libido, gynecomastia, and impotence, along with mental status changes like lethargy and confusion.

Proton Pump Inhibitors (PPIs)

A class of medications including Pantoprazole (Protonix) and Omeprazole (Prilosec) that block acid production by proton pumps in parietal cells.

PPI Adverse Effects

Long-term risks include osteoporosis and fractures related to hypocalcemia and hypomagnesemia, Cdiff-associated diarrhea, and rebound acid hypersecretion upon discontinuation.

PPI Nursing Care

Instruct patients to take the medication 30 minutes before eating and never to crush, chew, or break sustained-release capsules.

Sucralfate (Carafate)

A mucosal protectant that temporarily forms a coating over ulcers and erosions to protect them from acid and pepsin, allowing tissue to heal.

Antacids

Medications containing alkaline ions that neutralize gastric acid and stimulate prostaglandin production to maintain the mucosal layer; examples include Aluminum hydroxide, Magnesium hydroxide, and Calcium Carbonate (Tums).

Antacid Specific Adverse Effects

Aluminum and calcium cause constipation; magnesium causes diarrhea and potential hypermagnesemia in renal failure patients; sodium causes fluid retention.

Ondansetron (Zofran)

A serotonin antagonist used for emesis prophylaxis in chemotherapy and post-op recovery that blocks serotonin receptors in the chemoreceptor trigger zone (CTZ) and on afferent vagal neurons.

Serotonin Antagonist Nursing Care

Advised to obtain a baseline 12-lead EKG due to the risk of dose-dependent QT prolongation and monitor for serotonin syndrome and constipation.

Dopamine Antagonists (Antiemetics)

Medications like Promethazine (Phenergan) and Metoclopramide (Reglan) that target D2 receptors in the CTZ; adverse effects include extrapyramidal symptoms and neuromalignant syndrome.

Docusate sodium (Colace)

A surfactant laxative that lowers the surface tension of stools to allow water penetration, thereby softening the fecal mass.

Bulk-Forming Laxatives

Fiber-like agents such as Psyllium (Metamucil) that soften fecal mass and increase bulk; nursing care includes mixing powder forms in a full glass of liquid to prevent obstruction.

Stimulant Laxatives

Agents like Bisacodyl (Dulcolax) and Senna that stimulate intestinal peristalsis and increase water/electrolytes in the intestines; long-term use of suppositories can cause proctitis.

Osmotic Laxatives

Agents including Lactulose and GoLYTELY that draw water into the intestine to increase stool mass and stretch musculature, stimulating peristalsis.

Loperamide (Imodium)

An antidiarrheal that activates mu opioid receptors in the GI tract to decrease motility and increase sodium/water absorption, but should be held if Cdiff is suspected.

Alosetron (Lotronex)

A selective serotonin3 receptor antagonist used for severe IBS with diarrhea; requires monitoring for serious effects like ischemic colitis and hematochezia (rectal bleeding).

Lubiprostone (Amitiza)

A secretagogue medication for IBS with constipation that increases fluid secretion in the intestines to enhance motility.

Dicyclomine (Bentyl)

An antispasmodic that blocks acetylcholine on cholinergic receptors to relax GI smooth muscle and relieve cramping and bloating in IBS.

Ursodiol (Actigall)

A gallbladder medication that reduces cholesterol secretion in bile and increases bile acid content to dissolve or prevent gallstones.

Pancrealipase (Creon)

A mixture of lipase, amylase, and protease derived from pigs used to replace enzymes in patients with chronic pancreatitis or cystic fibrosis; must be taken before every meal.

Rifaximin

A broad-spectrum antibiotic used for hepatic encephalopathy that reduces ammonia-producing bacteria; can cause orange-red discoloration of urine, tears, and sweat.