GI drugs Flashcards
Calcium carbonate (Rolaids, Tums)
Class: Antacid Mech: Chemical reaction Thera: Ulcer treatment; GERD Important SE's: Milk-alkali syndrome, nephrocalcinosis, "rebound" acidity, digitalis antagonism Other SE's: Constipating effects
Sodium bicarbonate: differences from Ca carbonate
Important SE’s: Systemic alkalosis
Other SE’s: Enhanced effects of amphetamine, quinidine, and cinchophen
Misc: Rarely used due to causing systemic alkalosis
Magnesium hydroxide, magnesium carbonate (Maalox, Mylanta)
Important SE’s: Diarrhea (laxative effects)
Other SE’s: Hypokalemia, hypermagnesemia, iron deficiency
Misc: Magnesium toxicity mostly in presence of renal disease; liquid-based, so act fast
Aluminum hydroxide (Alternagel)
Important SE’s: Phosphate depletion and sequelae (weakness, anemia, tetany, apnea)
Other SE’s: Constipation
Misc: Safe for use in patients with renal failure (bonus: helps eliminate phosphate)
Atropine sulfate (Donnatol)
Class: Anticholinergics
Mech: Reduce acid secretion, reduce spasm; Relax all bowel smooth muscle (because most innervation of the bowel is cholinergic)
Thera: Ulcer treatment, Diarrhea
Important SEs: Anticholinergic effects
Misc: AKA, belladonna; contraindications: known pyloric obstruction, hiatal hernia, or peptic esophagitis (not used much)
Propantheline (Pro-Banthine); Metantheline bromide: differences from atropine sulfate
Thera: Ulcer treatment (taken 15-30 minutes before meals, and before bed)
Misc: Contraindications: known pyloric obstruction, hiatal hernia, or peptic esophagitis (not used much)
Cimetidine (Tagamet), Ranitidine
Class: Histamine (H2) receptor blocker
Mech: Inhibit 50-80% of 24 hour acid production
Thera: Ulcer treatment (first class to satisfy all 4 requirements); prophylactically for stress ulcers; GERD
Important SE’s: Rebound acidity if stopped suddenly
Other SE’s: Uncommon; headache, lethargy, confusion, depression, and hallucination
Misc: One dose as effective as multiple; binds and interferes with P450
Famotidine (Pepcid), Nizatidine (Axid): differences from the other -tidines?
Misc: One dose as effective as multiple
Misoprostol (Cytotec)
Class: ProstaglandinE analog
Mech: Decrease acid production, increase mucous and bicarbonate secretion
Thera: Ulcer treatment when prostaglandin production decreased (RA patients taking lots of NSAIDs)
Misc: Not very effective, since endogenous prostaglandin levels are already high in duodenal ulcer patients
Omeprazole (Prilosec), Lansoprazole (Prevacid)
Class: H/K/ATPase inhibitor
Mech: Inhibit >90% of 24 hour acid secretion (better than H2 antagonists); requires acid environment to activate (don’t take with antacids)
Thera: Ulcer treatment, treatment for H. pylori; GERD
Other SE’s: Headache, gynecomastia, gastric hyperplasia in humans and carcinoid tumors in rats long term (do not use long-term)
Misc: For H. pylori treatments, used with tetracycline, metronidazole, and clarithromycin; large P450 interference; lowest bioavailability (some P450 interference in Lanso with great bioavailability)
Rabeprazole (AcipHex), Pantoprazole (Protonix), Esomeprazole (Nexium): differences from the other prazoles
Thera: Ulcer treatment; GERD
Misc: Rabe with Moderate P450 interference, panto with No P450 interference; great bioavailability, esome with Some (?) P450 interference
Sucralfate (Carafate)
Class: Mechanical protectors
Mech: Coat the ulcer crater, increase mucosal resistance (requires acid environment)
Thera: Ulcer treatment, treatment for H. pylori
Important SE’s: Aluminum toxicity possible in renal failure
Misc: For H. pylori treatments, used with tetracycline, metronidazole, and clarithromycin; big pill, need to take 4 times per day
Bismuth salts (Pepto-Bismol)
Class: Mechanical protectors
Mech: Coat the ulcer crater, increase mucosal resistance
Thera: Ulcer treatment, treatment for H. pylori
Important SE’s: Aluminum toxicity possible in renal failure; turns bowel movements (and sometimes tongues) black
Misc: For H. pylori treatments, used with tetracycline, metronidazole, and clarithromycin
Metochlopramide (Reglan)
Class; Promotility agent (dopamine antagonist
Mech: Increase motor tone in lower esophageal sphincter (prevent reflux) and stomch (esp. antrum: improves gastric emptying); peripheral (stomach) and CNS (vomiting, via CRTZ) dopamine antagonist
Thera: GERD, anti-emetic, gastroparesis
Important SE’s: Hand tremor if used 4X/day (optimum use); possible extra-pyramidal symptoms, but not so severe
Misc: Can be used once/day for good effects
Cisapride (Propulsid)
Class: Promotility agent (dopamine antagonist
Mech: Increase motor tone in lower esophageal sphincter and stomch
Thera: GERD, gastroparesis
Important SE’s: Sudden cardiac death
Other SE’s: Not really used much anymore
Domperidone (Motilium)
Class: Promotility agent
Mech: Improves gastric tone
Thera: Gastroparesis