Chapter 81: Drugs for Peptic Ulcer Disease Flashcards
what is peptic ulcer disease
group of upper gastrointestinal disorders
- degrees of erosion of the gut wall
peptic ulcer disease cause
- imbalance between mucosal and aggressive factors
what are the defensive factors against peptic ulcer disease
- mucus
- bicarbonate
- blood flow
- prostaglandins
aggressive factors
- helicobacter pylori
- NSAIDS
- gastric acid
- pepsin
- smoking
H. pylori infection can lead to
- peptic ulcer disease
- gastric cancer
- mucosal lymphoma (MALT)
what population has higher rates of H. pylori infection
indigenous peoples
how do NSAIDS contribute to peptic ulcer disease
- inhibit the biosynthesis of prostaglandins
- reduce blood flow, mucus, and bicarbonate
how does gastric acid contribute to peptic ulcer disease
- directly injures cells of the GI mucosa and indirectly by activating pepsin
- Zollinger-Ellison syndrome
how does smoking contribute to peptic ulcers
- delays ulcer healing and increases risk for recurrence
what is the most common cause of ulcer development
H. pylori
what is the second most common cause of ulcer development
NSAIDS
what are the goals of drug therapy
- alleviate symptoms
- promote healing
- prevent complications
- prevent recurrence
what are the classes of antiulcer drugs
- antibiotics
- antisecretory agents
- mucosal protectants
- antisecretory agents that enhance mucosal defences
- antacids
drugs that reduce gastric acidity
antisecretory agents, misoprostol
drugs that enhance mucosal defenses
secralfate, misoprostol
NSAID induced ulcers treatment
- histamine blockers and PPIs (eg. omeprazole)
- discontinue use of NSAIDs
what drugs can cause peptic activity to increase
antacids, histamine 2 antagonists, PPIs
gastric Ph should be rasied above
5
Non-drug therapy
- Diet: 5-6 small meals a day
- smoking cessation
how to test for H pylori
- breath test
- serologic test
- stool test
- Invasive: endoscopic specimen
H. Pylori treatment
minimum of 2 antibiotics prescribed to reduce risk of developing resistance
- amoxicillin
- clarithromycin
- bismuth compounds
- tetracycline
- metromidozole
common side effects of antibiotics
- nausea, GI upset
- diarrhea
bismuth side effects
- black discoloration to the tongue and stool
antibiotic regimens goal
- minimize emergence of resistance; guidelines recommend using at least 2 antibiotics
treatment regimens
- PPI + amoxicillin + clarithromycin x 10-14 days
- PPI + metronidazole + clarithromycin x 10-14 days
- PPI + 3 antibiotics x 10-14 days
- PPI + bismuth + 2 antibiotics x 10-14 days
clarithromycin [Biaxin]
inhibiting protein synthesis
- rate of resistance is high
clarithromycin [Biaxin] most common side effects
- nausea
- diarrhea
- distortion of taste
amoxicillin
- rate of resistance is low
- antibacterial activity is highest at neutral pH and thus can be adhanced by reducing gastric acidity with antisecretory agent (e.g. omeprazole)
what is the msot common side effect of amoxicillin
diarrhea
how do bismuth compounds destroy H pylori
act topically to disrupt the cell wall casuing lysis and cell death
- also may inhibit urease activity (may prevent from adhering to the gastric surface)
bismuth compounds long term therapy
possible risk of neurologic injury
tetracycline
- inhibitor of bacterial protein synthesis
- resistance is rare
tetracycline should not be used in
pregnant patients and young children
- can stain teeth
tetracycline side effect
can stain teeth
metronidazole [Flagyl]
- very effective agianst sensative strains
- over 40% of strains are now resistant
metronidazole [Flagyl] most common side effect
nausea and headache
what should be avoided in patients takin metronidazole [Flagyl]
avoid alcohol
- reaction can occur
examples of Histamine 2 receptor antagonists
- Cimetidine [Tagamet]
- Famotidine [pepcid]
- Nizatidine [Axid]
histamine 2 receptor antagonists
- effects drug for treating gastric and duodenal ulcers
- promote healing by suppressing secretion of gastric acid
- side effects uncommon
therapeutic uses for all H2RA’s
- gastric doudenal ulcers
- GERD
- zollinger-ellison syndrome
- aspiration pneumonits
- heartburn, acid indigestion, sour stomach
therapeutic uses for cimetidine only
- molluscum contagiosum
- warts
Cimetidine [Tagamet] adverse effects
- antiandrogenic effects
- elevation of gastric pH may increase risk of pneumonia
- CNS effects: confusion, hallucinations
H2RAs should be taken
without meals
what is the msot effective drug for suppressing secretion of gastric acid
Proton Pump Inhbitors (PPIs)
Proton Pump Inhbitors (PPIs) therapeutic uses
Short term
- gastric/duodenal ulcers
- GERD
Proton Pump Inhibitors (PPIs) negatives
- cost and prescribers preference, DI’s swallowing abilities
- can increase risk of serious adverse events, including fracture, pneumonia, acid rebound, and possibly intestinal infection with Clostridium difficile
examples of PPI
omepazole [Losec]
omepazole [Losec]
prodrug converted in parietal cells
omepazole [Losec] side effects
- usually inconsequential with short term use
- headache
- GI: nausea, diarrhea, abdominal pain, flatulence
omepazole [Losec] adverse effects
- pneumonia (initial use)
- fractures
- hypomagnesemia
- rebound acid hyperssecretion
- c. difficile infection
Esomeprazole [Nexium] should be administered
- before meal
- in combination with naproxen [vimovo]
- daily dosing
Esomeprazole [Nexium] can be given
to children > 1 yr
Esomeprazole [Nexium] has better _____ than omeprazole
bioavailability
Lansoprazole [Prevacid]
- delayed release capsules and FasTabs
- NG tube, swallowing difficulties
- dose: 30mg daily
Dexlansoprazole [Dexilant]
- formulated as dual release capsule
- doses: 30-60 mg daily
- lower dose if moderate-severe hepatic impairment
omeprazole dose
- compunded suspension or delayed release tablet
- 20-40mg daily
Pantoprazole [Pantoloc]
- basically no drug interactions
- dose 40mg daily
- available in 2 salts
- avaliable IV
adverse effects when Pantoprazole [Pantoloc] is administered via IV
diarrhea, headache, nausea, dyspepsia, injection site reactions, including thrombophlebitis and abcess)
Rabeprazole [Pariet]
- fewer Di because less effect on CYP450
- dose 20mg daily (entric coated tab)
Sucralfate [Sulcrate] MOA
creates a protective barrier for up to 6 hours
Sucralfate [Sulcrate] therapeutic uses
- acute ulcers and maintence therapy
Sucralfate [Sulcrate] adverse effects
- constipations
Misoprostol [Cytotec] MOA
replaces andogenous prostiglandins
Misoprostol [Cytotec] therapeutic effects
- only approved for Gi indication is prevention of gastric ulcers cause by long term NSAID therapy
Misoprostol [Cytotec] adverse effects
- Most common; dose related diarrhea and abdominal pain
Misoprostol [Cytotec] is contradicted during
pregnancy
- category X
antacids MOA
react with gastric acid to produce neutral salts or salts of low acidity
what is the only antiacid that alters the systemic pH
sodium bicarbonate
antacids should be used with caution is patients with
renal impairment
Antacids adverse effects
- Constipation: aluminum hydroxide
- Diarrhea: magnesium hydroxide
- sodium loading
antacid drug interactions
- Cimetidine
- Sucralfate
antacid administration
seperate administration of antacid and other drugs by at least ONE HOUR
antacid families
- aluminum compounds
- magnesium compounds
- calcium compounds
- sodium compounds
Magnesium hydroxide [Milk of magnesium]
rapid acting, high acid-neutralizing capacity, produces long lasting effects
Magnesium hydroxide [Milk of magnesium] most prominent adverse effect is
diarrhea
Magnesium hydroxide [Milk of magnesium] is usually taken in combination with
aluminum hydroxide (antacid that promotes constipation)
Magnesium hydroxide [Milk of magnesium] is avoided in patients with
undiagnoised abdominal pain
Magnesium hydroxide [Milk of magnesium] is frequently used as a
laxative
Magnesium hydroxide [Milk of magnesium] is used with caution in patients with
renal failure
Aluminum Hydroxide [Amphogel]
- low acid neutralizing capacity
- slow acting; effects have long duration
- rarely used alone (combination with magnesium hydroxide)
Aluminum Hydroxide [Amphogel] caution
significant amounts of sodium
Aluminum Hydroxide [Amphogel] adverse effects
constipation
Calcium carbonate (tums)
- rapid acting, high acid neutralizing capacity, effects have long duration
- acid rebound
- low palatability
Calcium carbonate (tums) principle adverse effect
constipation
-eructation (belching) and flatulence
Sodium Bicarbonate (Eno)
- useful for treating acidosis and elevating urinary pH to promote excretion of acidic drugs after overdose
can Sodium Bicarbonate (Eno) be used to treat PUD
no
- can cause alkalosis
Sodium Bicarbonate (Eno)adverse effects
- can cause alkalosis (patients with renal failure)
- eructation and flatulence
- can exacerbate hypertension and heart failure
Simethicone (Ovol)
- used to reduce gas bubbles
- often an add-on in antacids
- also used for babies
