GI Drugs

H. Pylori and PUD

H. pylori infection (70% of cases); best treated with triple therapy (PPI and 2 antiobiotics); assess hygiene, water source, and reinfection risks

Gastroesophageal Reflux Disease (GERD)

persistent heartburn; weakening of LES, decreased secretions and esophageal motility

Lifestyle Modifications for GERD/PUD

Raise HOB, eat smaller, frequent meals, avoid lying down after meals, maintain healthy weight, avoid spicy/fatty foods, tobacco, alcohol, caffeine, alcohol

Major Drugs for GERD and PUD

PPIs, H2 antagonists, antacids, H. pylori antidote, anti-ulcer medications

Esomeprazole (Nexium), Lansoprazole (Prevacid), Pantoprazole (Protonix)

Inhibits H+/K+-ATPase (proton pump) enzyme in gastric parietal cells → blocks final step of acid secretion → ↓ gastric acid; take 30 mins before meal, suppresses for 24 hours; treats GERD and PUD

Ranitidine (Zantac), Cimetidine (Tagamet), Famotidine (Pepcid)

Blocks H2 receptors on parietal cells → ↓ gastric acid production (day+night); avoid antacids and foods that increase acid (fatty/spicy foods, alcohol, NSAIDs); treats GERD and PUD

Aluminum hydroxide (AlternaGel)

Antacid that neutralizes gastric acid (raises pH above 3), inactivates pepsin; constipation, phosphate deletion

Magnesium hydroxide (Milk of Magnesia)

Antacid that neutralizes gastric acid, can act as a laxative, fast-acting; diarrhea, hypermagnesemia in renal impairment

Calcium carbonate (Tums, Titralene)

Antacid that neutralizes stomach acid; constipation, kidney stones, rebound hyperacidity

Sodium bicarbonate (Alka-Seltzer, baking soda)

Antacid that neutralizes acid; fluid retention, contraindicated with HF

Nursing Concerns for Antacids

Check electrolytes and renal function; signs for GI bleeding; gives 2 hours before or after oral meds to prevent absorption issues

Sucralfate (Carafate)

Forms a protective barrier on ulcer surface; enhances mucosal defense and promotes healing; taken on empty stomach

Bismuth compounds (Pepto-Bismol)

Stimulates mucosal bicarbonate and inhibits prostaglandin production and H. pylori; used for ulcers and diarrhea

Misoprostol (Cyrotec)

Stimulates mucosal production and inhibits gastric acid production; prevents NSAID-induced ulcers; contraindicated in pregnancy

Metoclopramide (Reglan)

Blocks dopamine receptors in CTZ; faster emptying of stomach and decreased esophageal relaxation (less reflux); treats N/V and GERD  

Anticholinergic drugs

Blocks muscarinic receptors on partietal cells and gastric smooth muscle → ↓ gastric acid secretion and motility ↓ and spasms

Nausea and Vomiting

Reflex controlled by vomiting center in medulla oblongata; triggered by input from GI tract, inner ear, and chemoreceptor trigger zone (CTZ) in cerebral cortex; dehydration, electrolyte imbalance, vascular collapse

Ondansetron (Zofran)

Blocks serotonin (5-Ht3) receptors in GI tract and CTZ; prevents nausea and vomiting (post-op, post-chemo)

Meclizine, Scopatamine

Antihistamine/anticholinergics that blocks histamine/acetylcholinergic signals from inner ear to vomiting center → prevents motion sickness and vertigo

Metoclopramide (Reglan), Promethazine (Phenergan)

Antidopaminergics that blocks dopamine receptors in CTZ → reduced nausea and vomiting from drugs or anesthesia

Lorazepam (Ativan)

Benzodiazepine that depresses CNS and CTZ → reduces anxiety related N/V

Dexamethasone (Decadron)

Corticosteroid that blocks inflammation and CTZ activation → prevents chemo-induced N/V

Nursing Concerns for Antiemtic Agents

Assess nutritional, fluid, and electrolytes; NPO and lay on side to prevent aspiration; monitor EPS symptoms in elderly, extreme weight loss, and children

Psyllium Muculloid (Metamucil)

Bulk forming laxative that absorbs water to increase stool bulk and increase peristalsis; treats constipation; abdominal cramping, fainting with low fluid intake; take with full glass of water; 24-48 hours

Magnesium hydroxide (Milk of Magnesia), Polyethylene glycol (MiraLAX), Sodium biphosphate (Fleet phospho-soda)

Saline and osmotic laxatives that draws water into intestines to soften stools and stimulate bowel movement; dehydration, fluid, and electrolyte imbalances; 1-6 hrs in high doses (cathartic, rapid)

Bisacodyl (Dulcolax), castor oil (emulsoil)

Stimulant laxatives that stimulates persistalsis by irritating intestinal mucosa; bowel prep for exams/surgery; laxative dependence, fluid/electrolyte depletion; oral works (6-12), rectal (1-6)

Docusate (Colace)

Stool softener that increases water and fat absorption in stools; prevents constipation post-surgery, injury, or MI; abdominal cramping, diarrhea; 24-48 hrs

Mineral oil

Lubricant laxatives that lubricates stool and colon mucosa for easier passage; interferes with fat-soluble vitamin absorption; 24-48 hrs

Nursing Concerns for Laxatives

Assess GI and bowel movement; Diet and education; avoid long term to prevent dependence; determine cause before admin

Diphenoxylate + Atropine; (Lomotil)

Opioid-anticholinergic combo that slows intestinal peristalsis by acting on smooth muscle; treats severe diarrhea; constipation

Bismuth Subsalicylate (Pepto-Bismol)

For antidiarrheal, turns into salicylic acid in stomach → slows peristalsis; treats diarrhea, heartburn, and H. pylori; caution for toxicity, Reye’s syndrome in children w/ flu symptoms (avoid Aspirin)

Loparamide (Imodium)

Opioid antidiarrheal that slows intestinal peristalsis; less risk of dependence with no CNS effect

Octreotide (Sandostatin)

Somastatin analog that inhibits serotonin and other peptides; for diarrhea, reduces intestinal secretions

Nursing Concerns for Antidiarrheals

Assess bowel movements, stool frequency, color, consistency; check for blood; monitor hydration status; avoid caffeine and alcohol