1. Gastrointestinal Agents

2. ♦︎ gastrointestinal agents – used to treat disorders of the stomach and/or the intestines
♦︎ include
- enzymes
- antidiarrheals
- antiemetics
- anti-ulcer agents
- laxatives
- stool softeners

3. ♦︎ stomach lies in the ULQ of the abdomen between the lower end of the esophagus and the beginning of the small intestine (duodenum)
● mechanically and chemically breaks down food – (HCl and
pepsinogen) forming chyme (semi-fluid liquid)
● peristalsis (wave-like motion) moves food through the digestive
tract
♦︎ the small and large intestine make up ~28ft bowel
● most food absorption occurs in the small intestine
● large intestine absorbs water and connects to the rectum and anus
for waste (stool) elimination

4. ♦︎ the GI system (alimentary canal) and its accessory organs play a major role in normal body function
● dysfunction may require immediate attention – drug therapy,
medical or surgical intervention
● preventative care and early detection of pathology encouraged

5. Enzymes
♦︎ pepsin – normally present gastric enz – breaks down protein
♦︎ in the absence of pepsin, proteolytic enz from the pancreas that work in the small intestine can still break down protein to amino acids
♦︎ some conditions (cystic fibrosis / chronic pancreatitis) may require enz therapy – pancreatin or pancrelipase
♦︎ malabsorption conditions (steatorrhea)
where fat is inadequately digested and
excreted in the stool - may be treated
with pancrelipase

6. Antidiarrheals
♦︎ diarrhea – condition of frequent, watery stools (decrease in intestinal water absorption, increased secretion of electrolytes or an excessive amount of mucous production)
– may result from microorganisms (viral / bacterial), drug or stress
reaction
♦︎ antiperistalsis drugs – slow the movement of intestinal contents (increase water and electrolyte absorption)
● Immodium (loperamide) / Lomotil (diphenoxylate + atropine)
♦︎ secretion inhibitor – blocks the secretion of stomach acid and has antibacterial properties
● Pepto-Bismol (bismuth subsalicylate)
♦︎ infectious diarrhea antibiotics (metronidazole and vancomycin) may be indicated

7. Antiemetics
♦︎ treats condition of nausea and vomiting – usually a symptom or side effect of some other condition
● food / drug allergy or reaction, pregnancy, stress / anxiety,
exhaustion, viral / bacterial infection, cancer
♦︎ treatment is to reduce the hyperactivity of stimuli receptors and lower the impulse rate – dehydration and electrolyte imbalance are major concern with prolonged vomiting
● Compazine (prochlorperazine)

8. Antacid / Antiulcer Agents
♦︎ generally composed of inorganic salts (calcium carbonate, aluminum hydroxide, magnesium hydroxide) – neutralize existing acid in the stomach
♦︎ indicated at the onset of hypergastric activity – pain relieving, short acting and not strong enough for undiagnosed ulcers
● Maalox, Gaviscon, Mylanta, Rolaids, Tums
histamine receptor agonist
♦︎ inhibits the secretion of gastric acid by blocking the effects of histamine
● Zantac (ranitidine), Pepcid (famotidine)

9. GERD (gastroesophageal reflux disease) / peptic ulcer
♦︎ caused by hypergastric acidity that erodes tissue in localized areas of the esophagus, stomach and intestines
♦︎ most are benign and produce mild symptoms of discomfort – more serious extend to underlying layers of connective tissue and smooth muscle (bleeding)
♦︎ treatment includes bland diet and PPI (proton pump inhibitor)
♦︎ proton pump inhibitors (PPIs) reduce the production of acid by blocking the enzyme in the wall of the stomach that produces acid
● Prilosec (omeperazole) – now OTC
● Prevacid (lansoprazole) – now OTC
● AcipHex (rabeprazole)
● Nexium (esomeprazole) – now OTC (“purple pill”)
● Protonix (pantoprazole(

10. laxatives and stool softeners
♦︎ commonly prescribed to treat constipation – condition of dehydrated stool, infrequent bowel movements (often painful and difficult)
♦︎ change in diet, fluid intake and activity level
laxatives
♦︎ promote defecation without stress or pain
♦︎ bulk forming – swell when mix with intestinal contents (increase water)
♦︎ stimulant – irritate the lining and nerves of the intestine to move stool through the bowel
♦︎ saline – rapidly promote watery stools by drawing water into the intestine
♦︎ osmotic – increase stool water content through osmosis
stool softeners (emollient laxative)
♦︎ Colace (docusate sodium) – promotes the mixing of fatty and watery intestinal substances to soften the stool