Pharm GI Flashcards
Proton pump MOA
cAMP
Antacids
- Aluminum Hydroxide - constipation
- Magnesium hydroxide - diarrhea
Antacid interaction with mucosa
Protect through stimulation of prostaglandins production
Antacid regime for PUD
1-3hr after meals and at bedtime
H2-R antagonist
Cimetidine
Cimetidine interaction
CYP 450 (warfarin, phenytoin, theophylline)
Cimetidine SE
- CNS confusion (elderly)
- drowsy, fatigue
Antacid & H2 ant. indication
-GERD less than 3 times a week
Disorder nothing will work for
Non-ulcer dyspepsia
PPI
Omeprazole
PPI journey
prodrug in intestinal lumen
- protonated and concentrated in parietal cells canaliculi
- Active thiophilic sulfonamide
PPI MOA
Irreversible (covalent disulfide) block of H/K ATPase
PPI regime
1hr before meal
PPI metabolism
- t1/2 1.5hr
- duration 24hr
- first pass metabolism
PPI contraindication
Severe liver disease only
first-pass metabolism
Recurrence after PPI discontinuation
80% within 6 months
Peptic ulcer Tx
PPI (6 weeks)
Clarithromycin/Amoxicillin (2 weeks)
PPI doesn’t work for
- Nonulcer dyspepsia
- Prevention of stress gastritis
PPI SE
- Diarrhea
- B12 & mineral malabsorption
- Salmonella, shigella infection
-Sucralfate-
Sucrose/aluminum hydroxide
-Prevent bleeding in stress-related gastritis
-Misoprostol-
Prostaglandin E1 analog
- Increase mucosal blood flow, stimulate good stuff
- Prevent alcohol & NSAID ulcers
-Bismuth Subsalicylate-
- Direct antimicrobial against h.pylori
- Bind enterotoxins
-Bismuth-
SE
CI
- Tongue and stool blackening
- CI with renal insufficiency
-Metoclopramide-
Class
Indication
MOA
Prokinetic
GERD, antinausea (D2), delayed gastric emptying
5HT4 enteric neuron agonist -> Ach release
-Metoclopramide-
SE
CNS extrapyramidal manifestations (use short term)
First line constipation Tx
Diet, fluid, fiber, avoid drugs
MgO (magnesium oxide)
Osmotic laxative for acute constipation
-Docusate-
Laxative - allow water and lipids to penetrate stool
Antidiarrheals
Don’t use for bloody diarrhea, high fever, systemic toxicity
-Loperamide-
Opioid antidiarrheal
- Doesn’t cross BBB, no abuse
- Inhibits presynaptic cholinergic nerves
-Ocreotide-
Antidiarrheal - Somatostatin
- Inhibit secretory diarrhea
- Tx VIPoma and carcinoid tumor
-Lomotil-
Antidiarrheal
-Opiod (diphenoxylate) and atropine
-Alosetron-
Irritable Bowel Syndrome (severe, second line Tx)
-5-HT3 antagonist
-Sulfasalazine-
Indication
MOA
SE
Ulcerative Colitis
- 5-ASA (Aminosalicylic acid)
- Nausea, bone marrow suppression, hypersensitivity rxn
-Azathioprine-
Immunosuppressant for IBD
-6-Mercaptopurine
SE: Bone marrow suppression, hypersensitivity
-Methotrexate-
Crohn’s disease
-SE: Bone marrow suppression
Enhance safety of glucocorticoids for IBD
Administer folate supplements
-Inflimixab-
Bind TNF-a (pro TH1 cytokine)
-Odansetron-
Anti-emetic for chemotherapy
- 5-HT3 antagonist
- Doesn’t block D-R
-Aripepitant-
Anti-emetic for chemotherapy
-NK1 (neurokinin) receptor antagonist
-Promethazine-
Anti-emetic for migraines
-D2-R antagonist
-Droperidol-
Anti-emetic for surgery
-D2-R antagonist