Gastrointestinal Flashcards
Histamine 2 Receptor Antagonists
+ ranitidine (Zantac)
OTHER HISTAMINE 2 RECEPTOR ANTAGONIST: Famotidine; most end in -ine.
INDICATIONS: Duodenal and gastric ulcers, GERD, Zolinger-Ellision syndrome.
MODE OF ACTION: Blocks H2 receptors in stomach, reducing gastric acid secretion.
SIDE EFFECTS: Increased risk of bacterial colonization of stomach and respiratory tract due to decrease in gastric acidity.
Proton Pump Inhibitor
+ omeprazole (Prilosec)
OTHER PPIs: Pantoprazole; many end in -azole
INDICATIONS: Duodenal and gastric ulcers, GERD, Zollinger-Ellison syndrome.
MODE OF ACTION: Inhibits an enzyme needed for gastric acid secretion.
SIDE EFFECTS: GI upset, increased risk of osteoporosis with long-term use
Mucosal Protectant
+sucralfate (Carafate)
INDICATIONS: Duodenal ulcers primarily.
MODE OF ACTION: Reacts w/stomach acid to form a thick paste that adheres to ulcers.
SIDE EFFECTS: CONSTIPATION.
KEY POINTS: TAKE 1 HOUR BEFORE MEALS AND AT BEDTIME (4 TMES A DAY). Increase intake of fluids and fiber.
Antacids
+ aluminum hydroxide (Amphojel)
OTHER ANTACIDS: Magnesium hydroxide, sodium bicarbonate, calcium carbonate.
INDICATIONS: Peptic ulcer disease, GERD.
MODE OF ACTION: Neutralizes stomach acid.
SIDE EFFECTS: CONSTIPATION (ALUMINUM AND CALCIUM DIARRHEA (MAGNESIUM).
KEY POINTS: Take 1 hour and 3 hours after meals and at bedtime; take at least 1 hour before or after other medications.
Prostaglandins
+ misoprostol (Cytotec)
INDICATIONS: Prevention of gastric ulcers in patients taking NSAIDS; also induces labor by ripening the cervix.
MODE OF ACTION: Decreases stomach acid secretion, increases production of protective mucus and bicarbonate.
SIDE EFFECTS: Dysmenorhea, miscarriage, GI upset.
KEY POINTS: DO NOT ADMINISTER TO A PREGNANT WOMAN - WILL CAUSE MISCARRIAGE! Run pregnancy test first!
Antiemetics
+ ondansetron (Zofran)
INDICATIONS: Nausea and vomiting due to chemotherapy, radiation, post-op.
MODE OF ACTION: Blocks serotonin receptors in CTZ (chemoreceptor trigger zone).
SIDE EFFECTS: Headache, dizziness, GI upset.
KEY POINTS: Administer PRIOR to chemotherapy (vs. treating n/v that is already occurring).
Laxatives
PSYLLIUM: Bulk forming laxatives (softens stool and increases bulk).
DOCUSATE SODIUM: Surfactant laxative (softens stool by increasing water content).
BISACODYL: Stimulant laxative (stimulates peristalsis).
MAGNESIUM HYDROXIDE: Osmotic laxative (draws water into intestine, promotes peristalsis). Monitor for Mg toxicity and dehydration.
KEY POINTS: Laxatives are contraindicated for bowel obstructions. Encourage increased fiber and fluid intake, and regular exercise.
Laxative used for Hepatic Encepalopathy
+ lactulose (Cephulac)
INDICATIONS: Constipation, hepatic encephalopathy (USED TO DECREASE AMMONIA LEVELS and improve mental status of patients).
MODE OF ACTION: Lowers pH in colon, which promotes ammonia excretion.
SIDE EFFECTS: GI upset, electrolyte imbalances, hyperglycemia.
Antidiarrheal
+ loperamide (Imodium)
OTHER ANTIDIARRHEAL MEDICATIONS: Diphenoxylate plus atropine.
MODE OF ACTION: Stimulates opioid receptors in intestines, causing a decrease in motility and increased absorption of Na and water.
SIDE EFFECTS: Constipation, drowsiness. At high doses, diphenoxylate plus atropine can cause opioid and anticholinergic effects.
Prokinetic Agents
+ metoclopramide (Reglan)
INDICATIONS: N/V, gastroparesis, GERD.
MODE OF ACTION: Accelerates gastric emptying. Blocks dopamine and serotonin receptors in CTZ.
SIDE EFFECTS: Drowsiness, GI Upset, extrapyramidal symptoms (including rigidity, tremors, twitching, tardive dyskinesia, restlessness).
Irritable Bowel Syndrome (IBS) Medications
IBS W/DIARRHEA: Alosetron (Lotronex).
MODE OF ACTION: Blocks 5HT3 receptors, which increases firmness of stool and decreases urgency.
SIDE EFECTS: Constipation.
IBS W/CONSTIPATION: Lubiprostone (Amitiza).
MODE OF ACTION: Increases fluid secretion in intestine and intestinal motility.
SIDE EFFECTS: Diarrhea, nausea.
5-Aminosalicyclates
+ sulfasalazine (Azulfidine)
INDICATIONS: IBS, Crohn’s disease, Ulcerative colitis.
MODE OF ACTION: Inhibits prostaglandin synthesis, which decreases colon inflammation.
SIDE EFFECTS: Blood dycrasias (anemia), agranulocytosis), GI upset, rash, headache.
Iron Supplements
+ ferrous sulfate (oral)
+ iron dextran (IV/IM)
INDICATIONS: Iron-deficiency anemia.
SIDE EFFECTS: Oral: GI upset/constipation, TEETH STAINING (drink w/straw!), dark green/black stools (harmless), IM/IV: staining at IV site, hypotension, flushing.
KEYPOINTS: VITAMIN C INCREASES ABSORPTION. Take on empty stomach, 1 hour before meals. Increase fluids/fiber to prevent constipation. IF GIVING IM IRON DEXTRAN, USE Z-TRACK METHOD. Keep out of reach of children due to risk of fetal iron toxicity. Encourage increased intake of foods high in iron.
