GI Meds 2 Flashcards
Drugs to control gastric acidity and secretion
- antacids
- H2 receptor blockers
- Proton pump inhibitors (PPIs)
What do antacids do?
- neutralize stomach acid
- break down into salt and water
Makeup of antacids
- carbonate or hydroxide base combined with
- Al, Mg, Na, or Ca
How does an antacid work?
Base combines with excess hydrogen ions to increase intragastric pH
This may give some protection against H. pylori
aluminum
biggest adverse effects of antacids
- constipation
- diarrhea
When should antacids not be taken?
Within 2 hours of orally administered drugs that need gastric juices to dissolve them!
- warfarin
- digoxin
- iron supplements
- certain antibiotics
What type of drug are these?
- Tagamet
- Pepcid
- Axid
- Zantac
H2 receptor blockers
What are H2 receptor blockers?
Histamine receptors that diminish stomach parietal cell secretion of gastric acid
H2 receptor blockers can decrease damage from
NSAIDs
H2 receptor blockers are commonly used for
short and long term management of
- peptic ulcers
- GERD
H2 receptor blockers are generally well-tolerated, but these may occur
- HA
- dizziness
*original prescription agents now available OTC
H2 receptor blockers and tolerance and implications
- tolerance may occur
- may be better to administer every other day instead of daily
What type of drugs are these?
- Nexium
- Prevacid
- Prilosec
- Protonix
Proton Pump Inhibitors
What do PPIs do?
inhibit the enzyme responsible for secreting gastric acid
H+, K+ ATPase: known as the proton pump
effectiveness of PPIs
- extremely effective
- can decrease acid secretion 80-95%
What are some of the benefits to PPIs?
- may have some antibacterial protective effect against H. pylori
- may have some anti-inflammatory properties to decrease gastric irritation
**This is the drug class of choice for long-term mgmt
PPIs are usually well-tolerated, but some adverse effects are:
- may have acid rebound when d/c
- associated with gastric polyps
- affect Ca2+ metabolism
- may increase risk of C. diff
What is acid rebound?
increased secretion of gastric acid after prolonged use of PPI
PPI and calcium metabolism
lead to increased risk of hip and vertebral fx
