Gastrointestinal Flashcards
What types of drugs are used for gastrointestinal ulcers?
- Anatacids
- Alginates
- Proton pump inhibitors
- H2 antagonists
What are examples of proton pump inhibitors?
- Omeprazole,
- Lansoprazole
- Esomeprazole (active of omeprazole)
- Rabeprazole
- Pantoprozole
What is the mechanism of action of proton pump inhibitors?
- Binds to active pumps so taken after eating
- Max efficacy after 2-3 days
- Takes a few days to completely stop its effect as de novo synthesis of the channels are required
Why is the effect of PPIs not instantaneous?
-Delayed effect as not all pump active all the time
What are the uses of proton pump inhibitors?
- Inhibit all acid and decreases
- Zollinger ellis syndrome
- Gastric and Duodenal ulcers
What are the side effects of proton pump inhibitors?
- C.difficile risk especially when being taken with antibiotics
- Has an effect on calcium metabolism so long-term osteoporosis
What are the examples of H2 antagonists?
- Cimetidine
- Ranitidine
What is the mechanism of action of H2 antagonists?
- Blocks H2 receptor
- Dose twice daily due to short half life of the drug
What are the uses of H2 antagonists?
- Cheap
- Safe
- Inhibits stomach excretion
What are the side effects of H2 antagonists?
- Loose stools
- Even if you block one pathway you can still get the other pathways working to produce acid
- Cimetidine can give gynaecomastia so avoid in men
What are examples antacids?
Aluminium hydroxide (Maalox)
What is the mechanism of action of antacids?
-Works as buffers due to being alkali so gives a temporary relief
What are the uses of antacids?
Used for temporary relief of ulcer
What is an example of alginates?
-Gaviscon (compound alginate)
What is the mechanism of action of alginates?
-Forms a layer over gastric mucosa to prevent further insult to the mucosa
