A.38. Drugs used in peptic ulcer diseases. pharmacotherapy of peptic ulcer diseases. Flashcards
what are Aluminum hydroxide and Magnesium oxide?
antacids
what is the function of antacids
weak bases that neutralize the stomach acid by reacting with protons in the lumen of the gut
where is Aluminum hydroxide and Magnesium hydroxide absorbed from?
poorly absorbed from the bowel
how is aluminum hydroxide and Magnesium hydroxide given?
orally
what are the side effects of aluminum hydroxide (Al[OH]₃)?
constipation
what are the indications for giving Aluminum hydroxide and Magnesium hydroxide?
symptomatic relief of dyspepsia and heartburn
what is Famotidine?
H₂-receptor antagonist
how is famotidine and cimetidine given?
oral, parenteral
what is the duration of action of famotidine?
12-24 hours
are H₂-receptor antagonists (famotidine) inhibitors of cytochrome P450 enzymes?
yes
what is the function of H₂-receptor antagonists?
competitive inhibitors of H₂-receptors–> indirect effect on proton pump activity –> ↓ gastric acid secretion (mainly nocturnal)
which agents have a greater acid-suppressing effect- H₂-receptor antagonists or PPI’s?
PPI’s
what are the indications for giving famotidine and PPI’s??
GERD Peptic ulcer disease (PUD) H.pylori associated ulcers NSAID'S induced ulcers Zollinger Ellison syndrome
side effects of H₂-receptor antagonists
**famotidine has milder SE than cimetidine
GI distress
confusion, agitation (in elderly)
weak antiandrogenic effects (cimetidine)
What is omeprazole or Pantoprazole?
proton pump inhibitors (PPI’s)
what is the function of PPI’s?
irreversible, direct inhibitors of a proton pump (K⁺/H⁺ antiport) in gastric parietal cells
what are the 1st line agents for reducing stomach acidity?
PPI’s
how is omeprazole given?
orally
should be administered on an empty stomach
how is pantoprazole given?
IV
what is the T1/2 of PPI’s?
1-2 hours
the acid-suppressing effect lasts up to 24 hours
full acid-suppressing is reached within 3-4 days
what effect does omeprazole have on Clopidogrel?
omeprazole is an inhibitor of cytochrome P450 enzymes
↓ the antiplatelet effect of clopidogrel
what are the SE of PPI’s?
diarrhea, abdominal pain
headaches
↓ oral bioavailability of vitamin B12, iron, digoxin, and ketoconazole
↑ risk of respiratory and enteric infections
hypergastrinemia (ECL and parietal cells hyperplasia)
how do PPI’s cause hypergastrinemia?
there’s a loss of negative feedback of H⁺ on D-cells
what are Sucralfate and Misoprostol?
mucosal protective agents
what is Sucralfate and what’s it’s function?
Aluminium sucrose sulphate
- polymerizes on the GI luminal surfaces to form a protective gel-like coating of ulcer beds
- enhances PGE synthesis
- stimulates mucus and bicarbonate secretion
- enhances mucosal defense and repair
how are Sucralfate and Misoprostol given and how many times are they administered daily?
orally
4 times daily
what does sucralfate require for activation?
acidic pH
It’s a prodrug
what does sucralfate do?
improve healing after mucosal damage
prevent reoccurrence
side effect of sucralfate
constipation
what is Misoprostol
Prostaglandin (PGE₁) analogue
what is the function of Misoprostol?
mucus and bicarbonate secretion ↑
HCl secretion ↓
mucosal vascularity and blood flow ↑
when do we give Misoprostol?
NSAID’S induced ulcers (also prophylaxis)
when is Misoprostol CI?
in pregnancy (abortifacient)
a side effect of misoprostol
diarrhea
misoprostol and Diclofenac are combined to treat..
arthritis pain, in patients with high-risk GI bleeding/ulceration
what is the #1 triple therapy for H.pylori
‘BMT regimen’
Bismuth subsalicylate
Metronidazole
Tetracycline
what is the #2 triple therapy for H.pylori
Ranitidine bismuth citrate
Tetracycline
clarithromycin or Metronidazole
what is the #3 triple therapy for H.pylori
Omeprazole
clarithromycin
amoxicillin or metronidazole
what is the Quadruple therapy for H.pylori
"BOMT" Bismuth subsalicylate Omeprazole Metronidazole Tetracycline
