GI Pharm

Question 1

Goals of GI Pharmacology

Answer 1

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).

Question 2

Main GI disorders treated

Answer 2

Ulcers, GERD, diarrhea, constipation, emesis.

Question 3

Role of gastric acid

Answer 3

Essential for digestion, can cause peptic ulcers and GERD if uncontrolled.

Question 4

Peptic ulcers and GERD

Answer 4

Peptic ulcers: ulceration of the mucosal lining. GERD: gastroesophageal reflux disease, caused by leaking of gastric acid.

Question 5

Antacids - Goal

Answer 5

Neutralize stomach acids by combining with excess H+ to increase gastric pH.

Question 6

Antacids - Specific agents

Answer 6

Various OTC trade names (TUMS, Pepto-Bismol).

Question 7

Antacids - Adverse effects

Answer 7

Constipation (Al-containing), diarrhea (Mg-containing), electrolyte imbalances, altered pharmacokinetics of medications.

Question 8

H2 Receptor Blockers - Role of histamine

Answer 8

Stimulates H2 receptors in stomach to increase gastric acid secretion.

Question 9

H2 Receptor Blockers - Goal

Answer 9

Bind to H2 receptors to avoid activation and prevent histamine-activated release of gastric acid.

Question 10

H2 Receptor Blockers - Specific agents

Answer 10

Famotidine (Pepcid), Cimetidine (Tagamet), Nizatidine (Axid), Ranitidine (Zantac).

Question 11

H2 Receptor Blockers - Adverse effects

Answer 11

Headache, dizziness, mild GI problems (nausea, diarrhea, constipation), acid-rebound phenomenon.

Question 12

Proton Pump Inhibitors - Goal

Answer 12

Inhibit enzyme (proton pump) involved in secretion of acid from gastric cells.

Question 13

Proton Pump Inhibitors - Specific agents

Answer 13

Omeprazole (Prilosec), Pantroprazole (Protonix), Esomeprazole (Nexium), Lansoprazole (Prevacid), Dexlansoprazole (Kapidex).

Question 14

Proton Pump Inhibitors - Adverse effects

Answer 14

Acid rebound, gastric polyps (long-term use), decrease nutrient absorption, kidney problems.

Question 15

Anticholinergics

Answer 15

Blocks effects of acetylcholine and decrease gastric acid release, examples: Atropine, pirenzepine, telenzepine.

Question 16

Metoclopramide (Reglan)

Answer 16

Dopamine receptor antagonist, stimulates motility in upper GI and decreases GERD.

Question 17

Prostaglandins

Answer 17

Inhibit gastric secretion, no advantages over other drugs such as PPI.

Question 18

Sucralfate (Carafate)

Answer 18

Disaccharide with protective effects on stomach mucosa, forms a protective gel that shields the stomach lining.

Question 19

Antidiarrheal Agents - Goal

Answer 19

Decrease GI motility to reduce fluid loss.

Question 20

Antidiarrheal Agents - Specific agents

Answer 20

Opium Tincture (laudanum), camphorated opium tincture (paregoric), Diphenoxylate (Lomotil), Loperamide (Imodium).

Question 21

Antidiarrheal Agents - Adverse effects

Answer 21

Nausea, abdominal discomfort, constipation, drowsiness, fatigue, dizziness, smaller risk of tolerance and addiction with small doses.

Question 22

Bismuth Salicylate

Answer 22

Stimulates water and electrolyte absorption in lower GI, decreases secretions, antibacterial effects.

Question 23

Bile-sequestering agents

Answer 23

Sequester and bind bile acids within GI tract, examples: Cholestyramine (Questran), Colestipol (Colestid), Colesevelam (Welchol).

Question 24

Clonidine (Catapres)

Answer 24

Stimulates alpha-2 receptors in GI tract, increases absorption and normal GI movement.

Question 25

Laxatives and Cathartics - Overview and goals

Answer 25

Promote evacuation of bowel and defecation when normal bowel movements are impaired, cathartics promote lower GI evacuation more rapidly than standard laxatives.

Question 26

Bulk-forming laxatives

Answer 26

Absorb water and swell within GI tract, stretches the bowel and stimulates intestinal movement.

Question 27

Stimulant laxatives

Answer 27

Increase fluid accumulation within the small intestine or activate peristalsis, examples: Bisacodyl (Dulcolax), Castor Oil, Senna (Senokot).

Question 28

Hyperosmotic laxatives

Answer 28

Produce gradient that draws water into the bowel and small intestine, stimulates peristalsis, examples: Methylcellulose (Citrucel), Polycarbophil (Fiber Lax), Psyllium (Metamucil).

Question 29

Lubricants and stool softeners

Answer 29

Facilitate entry of water into the fecal mass, softens the stool for easier defecation, examples: Docusate (Colace), Mineral Oil (Fleet Mineral Oil).

Question 30

Adverse effects of laxatives

Answer 30

GI disturbances, nausea, cramps, GI irritation, spastic colitis, long-term use can cause fluid and electrolyte abnormalities, dehydration, acid-base imbalances, laxative dependence.

Question 31

Digestants

Answer 31

Aid in digestion of food, examples: Pancreatic enzymes (amylase, trypsin, lipase), bile salts.

Question 32

Emetics

Answer 32

Induce vomiting to empty stomach of poisons or ingested toxins, examples: Apomorphine, Ipecac.

Question 33

Antiemetics

Answer 33

Decrease nausea and vomiting, examples: Antihistamines, anticholinergics, used for motion sickness, surgery recovery, chemo/radiation.

Question 34

Cholelitholytic agents

Answer 34

Dissolve types of gallstones by decreasing cholesterol content of bile.

Question 35

Rehabilitation considerations - Common issues

Answer 35

Common among critically ill patients, stress-related damage, stress ulcerations, inactivity causes adverse GI effects.

Question 36

Rehabilitation considerations - Impact on rehabilitation

Answer 36

Overall should not impair rehabilitation, some dizziness and fatigue, resolve uncomfortable symptoms to increase participation.

Question 37

Rehabilitation considerations - Encouragement of use

Answer 37

Encourage use if symptoms occur.