GI Flashcards
Cimetidine
Ranitidine
Famotidine
Nizatidine
H2 blocker “tidine”
MOA: reversible block of Histamine H2 receptors
- decrease parietal cell stimulation –> decrease H+ secretion
- does not block ACh or gastrin stimulation of parietal cells
Use
- peptic ulcer
- gastritis
- esophageal reflux
Toxicity
- Cimetidine: Inhibits CYP450*
– anti-androgenic effects (prolactin release, gynecomastia, impotence, decrease libido)
– cross BBB (confusion, dizziness, headache)
– cross placenta
- Cimetidine + Ranitidine: decrease renal excretion of creatinine
Omeprazole Lansoprazole Esomeprazole Pantoprazole Dexlansoprazole
PPI "prazole" MOA: irreversibly inhibit H+/K+ ATPase in stomach parietal cells - inhibit primary active transport - blocks acid production from all stimuli of parietal cells Use - peptic ulcer - gastritis - esophageal reflux - zollinger ellison syndrome Toxicity - increased risk C. diff - pneumonia - hip fracture - deceased Mg2+
Bismuth
MOA: bind ulcer providing physical protection
- allow HCO3- secretion to reestablish pH gradient in mucous layer
Use:
- increase ulcer healing
- traveler’s diarrhea
Sucralfate
MOA: bind ulcer providing physical protection
- allow HCO3- secretion to reestablish pH gradient in mucous layer
Use:
- increase ulcer healing
- traveler’s diarrhea
Misoprostol
MOA: PGE1 analog - increase production and secretion of gastric mucous barrier - decrease acid production Use - PREVENT NSAID induced peptic ulcers - maintain patent ductus arteriosus - induce labor (ripens cervix) Toxicity - diarrhea - contraindicated in women of childbearing potential (abortifacient)
Octreotide
MOA: somatostatin analog Use: - acute variceal bleeds - acromegaly - VIPoma - Carcinoid tumor Toxicity: - nausea - cramps - steatorrhea
Aluminum hydroxide
Antacid
- affect absorption, bioavailability or urinary excretion of other drugs by altering gastric and urinary pH or by delaying gastric emptying
- hypokalemia
- Overuse: constipation, hypophosphatemia, proximal muscle weakness, osteodystrophy, seizures
aluMINIMUM amount of feces
Magnesium hydroxide
Antacid
- affect absorption, bioavailability or urinary excretion of other drugs by altering gastric and urinary pH or by delaying gastric emptying
- hypokalemia
- Overuse: diarrhea, hyporeflexia, hypotension, cardiac arrest
Osmotic laxative
- MOA: osmotic load to draw water out
- Use: constipation
- Toxicity: diarrhea, dehydration, bulimics use
Mg = must go to the bathroom
Calcium carbonate
Antacid
- affect absorption, bioavailability or urinary excretion of other drugs by altering gastric and urinary pH or by delaying gastric emptying
- hypokalemia
- Overuse: hypercalcemia, rebound acid increase, can chelate and decrease effectiveness of other drugs
Polyethylene glycol
Osmotic laxative
- MOA: osmotic load to draw water out
- Use: constipation
- Toxicity: diarrhea, dehydration, bulimics use
Lactulose
Osmotic laxative
- MOA: osmotic load to draw water out
- Use: constipation
- hepatic encephalopathy (gut flora degrade it into metabolites of lactic acid and acetic acid which promote nitrogen excretion as NH4+)
- Toxicity: diarrhea, dehydration, bulimics use
Infiliximab
MOA: Monoclonal TNF-alpha antibody Use: - Crohn's disease - ulcerative colitis - rheumatoid arthritis Toxicity - infection (reactivation of Tb) - fever - hypotension
Sulfasalazine
MOA: combo of sulfapyridine (antibacterial) and 5-aminosalicylic acid (Anti inflammatory) - activated by colonic bacteria Use - ulcerative colitis - crohn's disease Toxicity - malaise - nausea - sulfonamide toxicity - reversible oligospermia
Ondansetron
MOA: 5-HT3 antagonist - central acting anti-emetic Use: - control vomiting post-op and in patients undergoing cancer chemo Toxicity - headache constipation
Metoclopramide
MOA: D2 receptor antagonist - increased resting tone, contractility, LES tone, motility - no effect on colon transport time Use: - diabetic and post surgery gastroparesis - antiemetic Toxicity - increased parkinsonism effects - restlessness - drowsiness - fatigue - depression - nausea - diarrhea - interacts with digoxin and diabetic agents Contraindications - patients with small bowel obstruction - parkinson
