Anti-ulcer drugs Flashcards
Cimetidine, Famotidine, Nizatidine, and Ranitidine make up what class of medication?
Histamine (H2) Receptor Antagonists
Some of the H2 receptor antagonists are made with?
Antacids including calcium/magnesium
Where do H2 receptor antagonists act on?
Basolateral membrane of parietal cell
How long is the onset of action for H2 receptor antagonists?
How does this compare to antacids and PPIs?
How long does it take ulcers to heal?
Does it completely inhibit all acid production?
1) 0.5 to 2 hours
2) Longer than antacids, shorter than PPIs
3) 4-8 weeks
4) No, it only inhibits about 20-50%
Which H2 receptor antagonists adverse effect decreases testosterone binding to androgen receptor?
How does this affect men and women?
1) Cimetidine
2) Gynecomastia in men and galactorrhea in women
Why does cimetidine have a lot of drug-drug interactions?
Because it is a prototypical inhibitor of several CYP450 isoenzymes
Which H2 receptor antagonists should be used during pregnancy only if necessary?
Ranitidine and Famotidine
Lansoprazole, Dexlansoprazole, Omeprazole, Esomeprazole, Pantoprazole, and Rabeprazole make up what class of medication?
Proton Pump Inhibitors (PPIs)
What is the MOA of PPIs?
How long does it take to create a new steady state of pump activity?
1) Binds to sulfhydryl groups of H+/K+- ATPase at parietal cell secretory sites, thereby inhibiting gastric acid secretion
2) Several days
How long does it take for full symptom effects with PPIs?
How does this compare to H2 antagonists?
Does it completely inhibit all acid production?
How long does it take ulcers to heal?
1) Several days
2) Takes longer
3) Comes very close to it (up to 90%)
4) 4-8 weeks
What serious adverse effect can PPIs cause?
CDAD (Clostridium Difficile-Associated Diarrhea)
Why does omeprazole have a lot of drug-drug interactions?
Because it is a prototypical PPI for CYP450 inhibition
Which PPI should be used during pregnancy only if necessary?
Lansoprazole and pantoprazole
Sucralfate makes up what class of medications?
Surface Acting Agents
What is sucralfate made up of chemically?
An octasulfate of sucrose with Al(OH)3 added
What is the MOA for sucralfate?
What does it ultimately prevent?
What was Dr. Segars analogy of this to help cement its MOA?
1) Undergoes cross-linking due to stomach acid which creates a viscous, sticky polymer that adheres to epithelial cells around the ulcer
2) Prevents acid access to ulcer sites
3) It is the band-aid drug
How long should sucralfate be used for?
Short term therapy
What may sucralfate also stimulate?
What effect do the stimulated substances have?
How does it affect pH?
1) Local prostaglandin and mucus production and epidermal growth factor
2) Cytoprotection
3) It doesn’t
What site is sucralfate indicated for?
Can it be used for ulcers in other regions?
1) Duodenal ulcers
2) Yes
Why can sucralfate cause constipation or severe renal failure?
Because it contains aluminium
Because of possible drug interactions when should sucralfate be taken?
How is it dosed for active ulcers?
1) Two hours after other meds
2) QID
Misoprostol makes up what class of medications?
PGE1 Analog
What is the MOA of misoprostol?
Provides protective prostaglandin to gastric mucosa and reduces gastric acid release from parietal cell
How does misoprostol provide cytoprotection?
1) Stimulates bicarbonate and mucous production
2) Increases mucosal blood flow
Standard doses of misoprostol reduce which acid output?
Basal and nocturnal
What is misoprostol indicated for?
Prevention of NSAID induced gastric ulceration
What are the contraindications for misoprostol?
Pregnancy and IBD
What is the MOA for the bismuth compounds such as bismuth subsalicylate?
Antibacterial actions
While the OTC use for Bismuth compounds is for heartburn, what is ist prescription use for?
Used in combo with antibiotics and acid suppressant for H. pylori
What adverse effect is seen with bismuth compounds?
Black/dark regularly formed stool
Because of bismuth compounds many drug interactions when should it be taken?
Two hours after other meds
What is a relative contraindications for taking bismuth subsalicylate due to bleeding issues?
Patients on antiplatelets and anticoagulants
In general what is the regimen for treatment of H. pylori?
Combination therapy with at least two antibiotics and an acid reducer of either PPI or H2 blocker for about 10-14 days
Why might a patient with H. pylori have a false negative result on their gastric urease or urea breath test?
How can we prevent this?
1) Because within 4 weeks prior to the test the treatment regimen they were on suppressed the H. pylori
2) Avoid the use of tx agents 4 weeks prior to test
Describe the triple therapy regimen for treatment of H. pylori including duration, dosing, and which agents
1) 14 days
2) BID dosing for all agents
3) PPI
4) Clarithromycin
5) Amoxicillin or Metronidazole
Describe the quadruple therapy regimen for treatment of H. pylori including duration, dosing, and which agents
1) 10-14 days
2) PPI at BID, all others QID dosing
3) PPI
4) Metronidazole
5) Tetracycline
6) Bismuth subsalicylate
When choosing the antibiotics for treatment of H. pylori what would make you choose metronidazole over amoxicillin?
Patient has a penicillin allergy
Which H pylori treatment therapy should be used first?
What should be considered when this one fails?
1) Triple therapy
2) Move to quadruple therapy and switch antibiotics
While there are drug pacs that include most of the drugs needed for H pylori treatment, which one is missing in the regimen?
PPI
What should you consider doing after completion of the 10-14 day H. pylori combination therapy?
PPI therapy for a few/several weeks after
Which antibiotic can fail to treat H pylori due to community acquired resistance?
Metronidazole
If there is failure of eradication with metronidazole containing triple-therapy what should you do?
1) Stay on triple therapy but substitute it out with tetracycline
2) Switch to quadruple therapy with clarithromycin and amoxicillin as the antibiotics
What should you do when treating H pylori with clarithromycin resistance?
1) Substitute either amoxicillin or tetracycline
2) Consider Bismuth quadruple therapy
Which drug would you consider using on a pregnant patient without H pylori to treat PUD for a short course?
Which would you use in this scenario if the symptoms are moderate?
Which would you use in this scenario if the symptoms are severe?
1) Sucralfate
2) Ranitidine
3) Lansoprazole
In the treatment of PUD for a patient that is NSAID-at risk, what are some options you have if NSAID are not required or if they are required?
1) If NSAID is not required, consider acetaminophen
2) If it is required consider COX-2 NSAID and/or
consider PPI or Misoprostol
What are the H2 Receptor Antagonists?
1) Cimetidine
2) Famotidine
3) Nizatidine
4) Ranitidine
What are the Proton Pump Inhibitors?
1) Lansoprazole
2) Dexlansoprazole
3) Omeprazole
4) Esomeprazole
5) Pantoprazole
6) Rabeprazole
What is the Surface Acting Agents?
Sucralfate
What is the PGE1 Analog?
Misoprostol
