H2 Blockers, PPIs, H Pylori & Octreotide Flashcards
1
Q
Most Common Casues of PUD
A
- H. pylori infx
- Use of NSAIDs
- stress related mucosal damage (SRMD)
2
Q
H. Pylori infx
A
- gastritis infx caused by H. pylori bacteria (Gram -)
- infection that can be contracted during 1st few years of life -→ persists indefinitely unless treated
- transmitted fecal-oral
- commonly cause duodenal ulcers
3
Q
Risk factors for ulcers related to NSAIDs
A
- concomitant use of anticoagulants
- pre-existing coagulopathy (higher INR or thrombocytopenia)
- corticosteroid or SSRI use
- use of NSAIDs > 1 month
- high-dose NSAID use
- NSAID-related dyspepsia
- cigarette smokers
4
Q
Stress Related Mucosal Damage
A
- critically ill patients
- → often patients that are admitted are put on acid suppression therapy
- d/t compromised mesenteric perfusion
- develop within 1st few hours of serious illness
- tend to be superficial
- Causative conditions:
- sepsis, severe trauma, surgery , burn > 25% of BSA, mechanical ventilation, organ failure, coagulopathy, high dose steroid use (>250mg/d)
5
Q
Zollinger-Ellison Syndrome (ZES)
A
-
Gastrin producing tumor (gastrinoma)
- hypersecretion of gastric acid → diarrhea/ malabsorption
-
results in lots of ulcerations → high risk for perforation & bleeding
- tx: high dose PPI
- may be long term tx if tumor cannot be fully resected
- tx: high dose PPI
- Clinical Presentation:
- abd pain
- dyspepsia
- Complications:
- GI bleed
- obstruction (due to inflammation or scar formation)
- Perforation
6
Q
Diagnosis of PUD
A
-
Serologic:
- For newly infected patients only
- measures IgG levels, will remain elevated for a long time after eradication so not good for f/u treated patients
- false positives = increase with age
-
Urea Breath Test:
- Test should be used 2 weeks after PPI or H2 blocker or 4 weeks after abx
- drink urea beverage labelled with C13 or14
- wait 10-30 min then exhale breath into bag → if (+) → urea was metabolized by urease = presence of H. pylori
-
Stool antigen Assay:
- use for initial dx or confirm eradication
- avoid use d/t reduced sensitivity if:
- Abx within 4 weeks, PPI within 2 weeks, H2 blockers within 24 hours
7
Q
Non-Pharmacological tx of H. pylori
A
-
avoid risk factors:
- smoking
- alcohol use
- NSAID or ASAS
-
Surgery:
- reserved for complicated or refractory PUD
8
Q
Pharmacological tx of H. Pylori
A
Goals: complete eradication of bacteria
- 1st line: 4 drugs x 14 days:
- bismuth salicylate + TCN + metronidazole + PPI
- 3 drug regimen with PPIs:
-
Clarithromycin + amoxicillin + PPI
- if amox allergy → metronidazole
-
Clarithromycin + amoxicillin + PPI
- cure rate with H2 blockers = less than PPIs
-
duration of therapy = controversial
- guidelines recommend 10-14 days
- disadvantages of long duration = decreased adherence, increased cost
- guidelines recommend 10-14 days
9
Q
Chart for initial Approach to abx tx of H. pylori
A
10
Q
Parietal Cells, GI acid secretion, and the binding molecules
A
-
increased acid secretion:
- histamine, acetylcholine, gastrin
-
decreased acid secretion:
- prostaglandin E 2
11
Q
H2 Blockers MOA
A
- block the h2 receptors so that histamine cannot potentiate acid secretion from the parietal cell
- not as good as PPIs as gastrin and acetylcholine can still activate the acid secretion from the parietal cell
Used to help heal peptic ulcers or maintain ulcer healing
12
Q
H2 blockers
A
“-tidine”
Indications: GERD, adjunct h.pylori eradication
-
SEs:
- headache
- cimetidine (Tagamet)
- 3A4 and 2D6 inhibitor
- gynecomastia, impotence
- caution with hepatic dysfunction
- Ranitidine (Zantac)
- caution with hepatic dysfunction
- famotidine (Pepcid)
- avoid with lactation
- Nizatidine (Axid)
- anxiety, pruritus, nasopharyngitis
-
Precautions:
- Renal dysfunction
- Elderly
- Pregnancy
- Hypersensitivity
-
Precautions:
13
Q
Sucralfate MOA
A
protects from acid, but does not reduce acid in the stomach
- paste that you swallow that cross links with mucosal defects so that it can coat it and protect it
14
Q
Misoprostol
A
PGE1 (prostaglandin) analog
-
inhibits acid secretion and promotes mucosal defense
- superior to H2-blockers for prevention of NSAID-induced ulcers
-
indications:
- reduce risk of NSAID-induced gastric ulcers
-
SEs:
- abdominal pain
- flatulance
- diarrhea
- CONTRAINDICATIONS: Pregnancy → Abortifacient!!!!!
15
Q
Tx of Refractory Ulcers
A
when ulcers fail to heal despite 8-12 weeks of tx
- thorough assessment needs to be done:
- adherence, OTC/rx use, H. pylori testing, esophagogastroduodenoscopy with biopsy to r/p malignancy
- measure serum gastrin to r/o ZES
-
Considerations:
- changing H2 blockers to PPI
- increase dose of PPI if not at max dose
- Consult with GI!
17
Q
Approach to GERD tx: CHART
A
- lifestyle mods + standard dose H2-RAs BID for 6-12 weeks
- or → PPIs Qday for 4-8 weeks, can increased to BID if insufficient response
