Gastrointestinal- Pharmacology Flashcards
Histamine-2 blockers
- Names
- Clinical use
- Adverse effect
Cimetidine, ranitidine, famotidine, nizatidine
Peptic ulcer, gastritis, mild esophageal reflux.
Cimetidine is a potent inhibitor of cytochrome P-450; it also has antiandrogenic effects; can cross blood-brain barrier and placenta.
Proton pump inhibitors
- Names
- Clinical use
- Adverse effects
Omeprazole, lansoprazole, esomeprazole, pantoprazole, dexlansoprazole.
Peptic ulcer, gastritis, esophageal reflux, Zollinger-Ellison syndrome, therapy for H pylori, stress ulcer prophylaxis.
risk of C difficile infection, pneumonia, acute interstitial nephritis. serum Mg2+ with long-term use;
Antacids
- Name and adverse effect
Aluminum hydroxide: Constipation and hypophosphatemia; proximal muscle weakness, osteodystrophy, seizures
Calcium carbonate: Hypercalcemia (milk-alkali syndrome), rebound acid increase
Magnesium hydroxide: Diarrhea, hyporeflexia, hypotension, cardiac arrest
Bismuth, sucralfate
- Mechanism
- Clinical use
Bind to ulcer base, providing physical protection and allowing HCO3 secretion to reestablish pH gradient.
ulcer healing, travelers’ diarrhea (bismuth).
Misoprostol
- Mechanism
- Clinical use
- Adverse effects
PGE1 analog.
Prevention of NSAID-induced peptic ulcers. Also used off-label for induction of labor (ripens cervix).
Diarrhea. Contraindicated in women of childbearing potential (abortifacient).
Octreotide
- Mechanism
- Clinical use
- Adverse effects
Long-acting somatostatin analog; inhibits secretion of various splanchnic vasodilatory hormones.
Acute variceal bleeds, acromegaly, VIPoma, carcinoid tumors.
Nausea, cramps, steatorrhea. risk of cholelithiasis
Sulfasalazine
- Mechanism
- Clinical use
- Adverse effects
combination of sulfapyridine (antibacterial) and 5-aminosalicylic acid (anti-inflammatory).
Ulcerative colitis, Crohn disease (colitis component).
Malaise, nausea, sulfonamide toxicity, reversible oligospermia.
Loperamide
- Mechanism
- Clinical use
- Adverse effects
Agonist at μ-opioid receptors; slows gut motility. Poor CNS penetration (low addictive potential).
Diarrhea
Constipation, nausea.
Ondansetron
- Mechanism
- Clinical use
- Adverse effects
5-HT3 antagonist; dicrease vagal stimulation. Powerful central-acting antiemetic
Control vomiting postoperatively and in patients undergoing cancer chemotherapy.
Headache, constipation, QT interval prolongation, serotonin syndrome.
Metoclopramide
- Mechanism
- Clinical use
D2 receptor antagonist. increase resting tone, contractility, LES tone, motility, promotes gastric emptying. Does not influence colon transport time.
Diabetic and postsurgery gastroparesis, antiemetic, persistent GERD.
Metoclopramide
- Adverse effects
parkinsonian effects, tardive dyskinesia. Restlessness, drowsiness, fatigue, depression, diarrhea. Drug interaction with digoxin and diabetic agents.
*Contraindicated in patients with small bowel
obstruction or Parkinson disease.
Orlistat
- Mechanism
- Clinical use
- Adverse effects
Inhibits gastric and pancreatic lipase
Weight loss
Abdominal pain, flatulence, bowel urgency/frequent bowel movements; decrease absorption of fat-soluble
vitamins
Laxatives
- Bulk-forming laxatives
- Osmotic laxatives
- Stimulants
- Emollients
Psyllium, methylcellulose
Magnesium hydroxide, magnesium citrate, polyethylene glycol, lactulose
Senna
Docusate
- Indicated for constipation or patients on opiates requiring a bowel regimen.
Aprepitant
- Mechanism
- Clinical use
Substance P antagonist. Blocks NK1 (neurokinin-1) receptors in brain.
Antiemetic for chemotherapy-induced nausea and vomiting.
