PUD Flashcards
How many in the US population develop PUD in their lifetime?
10%
What are the causes of PUD?
- H pylori
- NSAIDs
- stress related mucosal damage
- Zollinger-Ellison syndrome
What is a potential risk factor for PUD?
smoking
Pathophysiology of PUD
-imbalance between factors in GI tract that break down food and factors that protect and repair the mucosa
How do duodenal ulcers present?
- pain 1-3 hours after meals
- pain may be relieved by food
How do gastric ulcers present?
- pain immediately after meals
- food often aggravates pain
What are the goals of PUD treatment?
- resolve symptoms
- reduce acid secretion
- promote epithelial healing
- prevent ulcer-related complications and recurrence
- eradicate H pylori if present
What is the non-pharmacologic treatment for PUD?
Eliminate or reduce:
- psychological stress
- cigarette smoking
- EtOH consumption
- NSAID or aspirin use
MOA Histamine Blockers
-inhibit gastric acid secretion
competitive inhibition of histamine at H2 receptors of gastric parietal cells
Histamine Blockers Generic Names
- “tidine”
- Cimetidine
- Ranitidine
- Famotidine
- Nizatidine
Cimetidine Trade Name
Tagamet
Famotidine Trade Name
Pepcid
Nizatidine Trade Name
Axid
Ranitidine Trade Name
Zantac
Histamine Blockers Adverse Effects
- well tolerated
- N/V/D
- rare bone marrow suppression, hepatotoxicity
- confusion, hallucinations, seizures w/ IV cimetidine (rare)
- gynecomastia, impotence w/ prolonged or high cimetidine doses
- reduce does w/ renal impairment
Drug Interactions of Histamine Blockers
- cimetidine increases plasma concentration of anticoagulants, theophylline, phenytoin
- others do not have significant interactions
MOA of Proton Pump Inhibitors
- decrease acid secretion (more than H2RAs)
- inhibit H+/K+ ATPase (proton pump) of parietal cells
Generic Names of PPIs
- “prazole”
- Omeprazole
Omeprazole Trade Name
Prilosec
PPIs Adverse Effects
- well-tolerated
- N/D, HA, dizziness, skin rash
- rebound acid hypersecretion
Why must overuse of PPIs be avoided?
- fracture risk due to decreased calcium absorption
- increased risk of pneumonia of C diff
- decreased magnesium
PPI Drug Interactions
- CYP450 2C19 inhibitor
- decreases clopidogrel’s active metabolite levels and anti-platelet activity by half (worse cardiovascular outcomes)
- alters absorption of some medications (due to hi pH)
When should PPIs be dosed?
30-60 min before AM meal
Prostaglandin MOA
-replaces protective PGs (NSAIDs decrease PG production)
Prostaglandin Generic and Trade Name (1)
-misoprostol (Cytotec)
AEs of Prostaglandin/Misoprostol
- diarrhea in 30-40% (start low and titrate up)
- uterine contraction (preg cat X)
- abdominal pain, nausea, flatulence
Drug Interactions of PG
-may increase effect of oxytocin (hence uterine contraction and preg cat X)
MOA of Sucralfate
- forms protective barrier in stomach
- weak acid neutralizer
Trade Name of Sucralfate
Carafate
AEs of Sucralfate
- constipation
- safe in pregnancy
Drug Interactions of Sucralfate
-chelation of phenytoin, warfarin, quinolones, thyroxine
MOA of Bismuth Preparations
- possible local gastroprotective effect
- stimulation of PGs
- suppression of H pylori
Trade Name of Bismuth Subsalicylate
Pepto Bismol
AEs of Bismuth Preparations
- black stool or tongue
- may cause salicylate sensitivity
- caution in older pts or renal failure
- caution in kids, flu, herpes zoster (Reye’s syndrome)
Drug Interactions of Bismuth Preparation
- toxicity of ASA, warfarin or hypoglycemics may be increased
- may decrease GI absorption and bioavailability of tetracyclines
PPI Ulcer Healing Duration
4 weeks
H2RA and Sucralfate Ulcer Healing Duration
6-8 weeks
What is the general treatment for PUD management?
not looking for specific meds
ulcer healing therapy (eg PPI, H2RA) + specific ulcer type therapy (eg NSAID, H pylori) +/- maintenance therapy
What type of dosing is recommended for large gastric ulcers?
-higher dose or longer duration
When will H2RAs and PPIs start to provide symptom relief?
within 1 week
H pylori causes what % of ulcers?
90% duodenal and 80% gastric
What is the H pylori rate of re-infection?
1%/year
How much of the world population is colonized by H pylori?
50%, 30% in US
Nonendoscopic H pylori Diagnostic Tests
- urea breath test
- serological testing
- stool antigen
Endoscopic H pylori Diagnostic Tests
- histology
- culture
- biopsy (rapid) urease
How might H pylori tests result in a false negative?
- abx or bismuth taken within previous 4 weeks
- PPI taken w/in previous 2 weeks
Best Regimens for Hy Pylori treatment are…
- simple
- well-tolerated
- cost-effective
- encourage patient compliance
- eradicate >90%
- minimize resistance
H Pylori PUD regimens must contain what drugs?
- 2 or more abx
- antisecretory drug (H2RA or PPI)
What is first line H pylori PUD therapy?
- sequential therapy
- PPI plus amoxicillin 1 gm PO BID x 5 days
- then PPI plus clarithromycin 500 mg and tinidazole 500 mg BID x 5 days
- PPI continues for 2-4 more weeks
What is second line H pylori PUD therapy?
-quadruple therapy
-bismuth subsalicylate 2 tabs qid plus
tetracycline 500 mg qid plus
metronidazole 500 mg tid plus
PPI bid
How can we avoid H pylori resistance? How can H pylori cure be confirmed?
- full course of therapy 10-14 days is best
- confirm cure with urea breath test or stool antigen >8 weeks after end of treatment
NSAID GI Adverse Effects
- nuisance sxs, eg dyspepsia
- mucosal lesions
- serious GI complications (>100,000 hospitalizations, >20,000 deaths/yr)
How do NSAIDs cause mucosal damage>
- direct or topical irritation of gastric epithelium
- systemic inhibition of endogenous GI mucosal PG synthesis
What are the established risk factors for NSAID induced ulcers?
- age >60
- prior PUD or GI bleed
- high dose or more toxic NSAIDs
- concomitant use of corticosteroids, oral bisphosphanates, SSRIs, antiplatelets (ASA, clopidogrel), anticoagulants
- chronic illness (eg cardiovascular dz)
What are possible risk factors for NSAID induced ulcers?
- NSAID-related dyspepsia
- H pylori infection
- rheumatoid arthritis
- EtOH use
What are the nonsalicylates?
- nonselective NSAIDs: ibuprofen, naproxen
- partially selective NSAIDs: etodolac, meloxicam
- COX2 inhibitors: celecoxib
What are the salicylates?
- acetylated: aspirin
- non-acetylated: salsalate, trisalicylate
NSAIDs with the Lowest GI Toxicity
COX2 inhibitors (celcoxib - celebrex)
NSAIDs with Low GI Toxicity
ibuprofen and meloxicam
NSAIDs with Intermediate GI Toxicity
naproxen
indomethacin
ketoprofen
diclofenac
NSAIDs with High GI Toxicity
ketorolac
piroxicam
What is considered a low risk GI patient for NSAID therapy?
- no risk factors
- age < 60
- no aspirin
- no prior ulcer or hx of ulcer-related GI complication
What NSAID therapy should a low risk GI patient have?
N-NSAID or P-NSAID
What is considered a moderate risk GI patient for NSAID therapy?
-1-2 risk factors
What NSAID therapy should a moderate risk GI patient have?
N-NSAID or P-NSAID plus PPI or misoprostol therapy; COX-2
What is considered a high risk GI patient for NSAID therapy?
- 3+ risk factors or concomitant use of low dose aspirin and either corticosteroids, warfarin or clopidogrel
What NSAID therapy should a high risk GI patient have?
N-NSAID or P-NSAID or COX-2 plus PPI or misoprostol therapy
What is considered a very high risk GI patient for NSAID therapy?
-prior ulcer or ulcer-related GI complication plus additional risk factors (age, concomitant use of low dose aspirin, warfarin, corticosteroids, or clopidogrel)
What NSAID therapy should a very high risk GI patient have?
N-NSAID or P-NSAID or COX-2 plus PPI or misoprostol therapy
consider doing PPI and misoprostol
Target Dose of Misoprostol Therapy
200 mcg TID
What type of ulcer prevention can H2RAs be used for?
duodenal
What treatments are not effective for preventing NSAID-induced PUD in high risk patients?
- COX-2 inhibitors
- sucralfate
- antacids
How should NSAID-induced ulcers be treated?
- PPI, H2RA, or sucralfate
- STOP NSAIDs! (or at least reduce dose), switch to acetaminophen for analgesia
Who might have stress-related mucosal damage (SRMD)?
-critically ill patients with risk factors including multiple trauma or multi system organ failure
What is the primary pathogenic factor with stress-related mucosal damage?
-mucosal ischemia due to decreased gastric blood flow
Prevention Options for Stress-Related Mucosal Damage
- PPI
- H2RA
- antacids
- sucralfate
Dosing for Zollinger-Ellison Syndrome
-omeprazole, lansoprazole, or rabeprazole 60mg/day
What is the second line therapy for Zollinger-Ellison syndrome?
-octreotide
Indications for PUD Maintenance Therapy
- frequent ulcer recurrence
- hx of ulcer-related bleeding
- healed refractory ulcer
- failed H pylori eradication
- heavy smokers
- continuous NSAID therapy
PUD Treatment Monitoring
- ulcer symptoms
- alarm signs and symptoms
- medication adverse effects