GI Pharm Flashcards
Goals of GI Pharmacology
Food digestion, nutrition and water absorption, gastric acid control and secretion, manage excessive GI motility (diarrhea), manage inadequate bowel evacuation (constipation), manage problems with digestion and vomiting (emesis).
Main GI disorders treated
Ulcers, GERD, diarrhea, constipation, emesis.
Role of gastric acid
Essential for digestion, can cause peptic ulcers and GERD if uncontrolled.
Peptic ulcers and GERD
Peptic ulcers: ulceration of the mucosal lining. GERD: gastroesophageal reflux disease, caused by leaking of gastric acid.
Antacids - Goal
Neutralize stomach acids by combining with excess H+ to increase gastric pH.
Antacids - Specific agents
Various OTC trade names (TUMS, Pepto-Bismol).
Antacids - Adverse effects
Constipation (Al-containing), diarrhea (Mg-containing), electrolyte imbalances, altered pharmacokinetics of medications.
H2 Receptor Blockers - Role of histamine
Stimulates H2 receptors in stomach to increase gastric acid secretion.
H2 Receptor Blockers - Goal
Bind to H2 receptors to avoid activation and prevent histamine-activated release of gastric acid.
H2 Receptor Blockers - Specific agents
Famotidine (Pepcid), Cimetidine (Tagamet), Nizatidine (Axid), Ranitidine (Zantac).
H2 Receptor Blockers - Adverse effects
Headache, dizziness, mild GI problems (nausea, diarrhea, constipation), acid-rebound phenomenon.
Proton Pump Inhibitors - Goal
Inhibit enzyme (proton pump) involved in secretion of acid from gastric cells.
Proton Pump Inhibitors - Specific agents
Omeprazole (Prilosec), Pantroprazole (Protonix), Esomeprazole (Nexium), Lansoprazole (Prevacid), Dexlansoprazole (Kapidex).
Proton Pump Inhibitors - Adverse effects
Acid rebound, gastric polyps (long-term use), decrease nutrient absorption, kidney problems.
Anticholinergics
Blocks effects of acetylcholine and decrease gastric acid release, examples: Atropine, pirenzepine, telenzepine.