GI Pharmacology Flashcards
Drug Therapy for GERD and PUD
H2 receptor antagonists Proton pump inhibitors Mucosal Protectants Antacids Antiemetics
Upper GI Distress: Increasing Protective Factors
Antacids
Sucralfate
Protective Factors: Mucus Bicarbonate Blood flow Prostaglandins
Upper GI Distress: Decreasing Aggressive Factors
Treating H. pylori
H2 Blockers
Proton Pump Inhibitors
Aggressive Factors: H. pylori NSAIDS Acid Pepsin Smoking
Treating H. Pylori
Requires several antibiotics W/ gastric acid inhibitor
Why a combo therapy for H. pylori?
Minimize resistance, H. pylori likes acidic environment
Length of Rx for H. pylori
10-14 days
Adherence: $200 w/ up to 12 pills
2 types of drugs to decrease gastric acid production
- Block H2 receptors (formoterol)
2. Inhibit proton pump (PPI)
H2 Receptor Antagonists
cimetidine (Tagamet)
famotidine (Pepcid)
H2 receptor antagonists MOA
- Blocks H2 receptors in the stomach
- Blocks gastric acid secretion by 60-70%
- Increases stomach pH
Route: PO, IV
-Give one hour apart from antacids
Indications for H2 Receptor Antagonists
GERD
PUD
Ulcer prophylaxis
Heartburn/dyspepsia
H2 Adverse Effects
Well tolerated
CNS effects in elderly
Slight Inc risk for PNA in elderly
H2 receptor Interactions
- Inhibit CYP 450 enzymes
- Newer generation H2RAs do not have this problem (Pepcid)
Safety alert:
- Can decrease levels of WARFARIN, phenytoin, theophylline
- Give IV form slowly to avoid bradycardia
PPI MOA
-Binds to Proton Pump
-Inhibits the hydrogen
potassium ATPase enzyme system (proton pump)
- Irreversibly inhibits the secretion of HCL
- MORE effective than H2RA
PPI indications
Short term use:
PUD
GERD
PPI Adverse Effects
Short-term: Safe
Long-term: Inc risk for PNA, Bone loss/Hip fx, stomach CA
Few drug interactions
Nursing: short-term only
Sucralfate (Carafate)
Class: Mucosal protectant
Unique drug composed of:
- sucrose-base
- Aluminum hydroxide
Sucralfate (Carafate): MOA
- Alters when exposed to gastric acid
- Sticky, thick gel (protective barrier)
Indications: Duodenal ulcers (FDA approved) Gastric ulcer (Not FDA approved)
Sucralfate (Carafate): AE and Route + interactions
PO (tab or suspension)
AE: no major, constipation
Interactions:
- DECREASED DRUG ABSOPTION
- PO: take 2 hours apart
Antacids
Aluminum (Amphojel)
SE: constipation
Magnesia (MOM)
SE: diarrhea
Calcium (TUMS)
SE: constipation
Aluminum + Mg (Maalox, Mylanta)
SE: balanced approach
Antacids MOA
Neutralize acid by 50%
Antacid Indication
PUD
GERD
Stress ulcers
Heartburn + Indigestion
Antacid Adverse Effects
Diarrhea + Constipation
Acid rebound
Interactions:
- Chelation
- Altered gastric absorption of many drugs
- Separate other drugs by 1 to 2 hours
