GI & Peptic 2 Flashcards
PPI
- Bioavailability of all agents is decreased by what?
- How is this fixed?****
- Bioavailability of all agents is decreased by what?
- How is this fixed?****
- Food***
- Administer approximately 30 - 60 mins BEFORE a meal (usually breakfast)***
(Know this)
PK of PPIs
- Acid inhibition lasts up to __ hours.
- How many hours are required for synthesis of new H+/K+-ATPase pump molecules
- Undergo which rapid 1st pass systemic effect?
- Which type of clearance neglible?
Acid inhibition lasts up to 24 hours.
hours required for synthesis of new H+/K+-ATPase pump molecules: 18 hours
1st pass hepatic
PK of PPIs
- Dose reduction in pts w/ what condition?
- Severe liver impairment
Which nerve stimulates postganglionic neurons of the enteric nervous system to release acetylcholine (ACh), which binds to M3 receptors on parietal cells and ECL cell?
Vagus
3 SE of PPIs
- Diarrhea**
- HA
- Abdominal pain
PPI adverse effects
- Acid is important in releasing what from food?
- Acid also promotes absorption of what 3 food bound minerals?***
- What should you monitor?
- What could you supplement with?
- Releasing B12 from food
- 3 food-bound minerals: iron, Ca, Mg*** (know this)
- Monitor: bone density
- Ca supplements
Adverse effects of which agent?
- Community-acquired respiratory infections and nosocomial pneumonia
- 2- to 3-fold increased risk for hospital- and community-acquired Clostridium difficile infection
- Salmonella, Shigella, E coli, Campylobacter
PPI
PPI Drug Interactions
- Decreased gastric acidity may alter absorption of what 4 drugs? Which drug especially?**
- Ketoconazole
- Itraconazole
- Digoxin***
- Atazanavir
“A KID”
PPI Drug Interactions
Omeprazole may inhibit the metabolism of what 3 drugs?
- Warfarin***
- Diazepam
- Phenytoin
“Omeprazole went to War w/ P. diddy”
PPI Drug Interactions
- Which 2 PPIs have no significant drug interactions?
- Rabeprazole
- Pantoprazole
“A rabbi wearing pants is getting no action…”
PPI Drug Interactions
- Metabolized by P450 cytochromes
- What is the “prodrug” which requires activation by the hepatic P450 CYP2C19?
- PPIs could reduce activation of what drug?
- Clopidogrel
- Clopidogrel
PPI Drug Interactions
- Which 2 PPIs are preferred bc/ of minimal CYP2C10 inhibition?
Rabeprazole & Pantoprazole
“Rabbi wearing Pants”
Mucosal Protective Agents
- Gastroduodenal mucosa evolved defense mechanisms to protect itself against the noxious effects of what 2 substance?
- acid & pepsin
What substance appears to be important in stimulating mucus and bicarbonate secretion and mucosal blood flow?
Mucosal prostaglandins
What are the 3 Mucosal Protective Agents?
- Sucralfate
- Prostaglandin analogs
- Bismuth
Which Mucosal Protective Agent?
- Salt of sucrose complexed to sulfated aluminum hydroxide
- forms a viscous, tenacious paste that binds selectively to ulcers or erosions for up to 6 hours
Sucralfate
Which Mucosal Protective Agent?
- Negatively charged sucrose sulfate binds to positively charged proteins in the base of ulcers or erosion
- Forms a physical barrier that restricts caustic damage
- Stimulates mucosal prostaglandin and bicarbonate secretion
Sucralfate
Which Mucosal Protective Agent?
- Used to prevent stress-related bleeding
Sucralfate
Adverse effects of which Mucosal Protective Agent?
- Small amount of aluminum is absorbed
- Do not be used for prolonged periods in patients with renal insufficiency
Sucralfate
Prostaglandin Analogs
- What are the 2 primary prostaglandins?
E & F
What is the name of a prostaglandin analog? (Methyl Analog of PGE1)
Misoprostol
Misoprostol (prostaglandin analog)
- Metabolized to what?
- Serum half life is how long?
- Excreted how?
- Metabolized to a metabolically active free acid
- Half life: less than 30 mins
- Excreted in the urine
T/F
- Dose reduction of Misoprostol is NOT needed in pts w/ renal insufficiency
True
Prostaglandin Analogs: Misoprostol
Pharmacodynamics
- Has what 2 properties?
- Binds to prostaglandin receptor on parietal cells, reducing histamine stimulated _____ production and causing modest acid inhibition
- Prostaglandins stimulate what 3 things?
Prostaglandin Analogs: Misoprostol
Has what 2 properties?
Acid inhibitory & Mucosal protective properties
Binds to prostaglandin receptor on parietal cells, reducing histamine stimulated cAMP production and causing modest acid inhibition
- Prostaglandins stimulate what 3 things?*
1. Intestinal electrolyte & fluid secretion
2. Intestinal motility
3. Uterine contractions
Which medication?
Reduces the incidence of NSAID-induced ulcers
Misoprostal
(Prostaglandin Analog)
Adverse reactions of which medication?
uterine contractions
do not use in pregnancy/childbearing women unless they have a neg. serum pregnancy test and on effective contraceptive measures
Misoprostol
(Prostaglandin Analog)
What are the 2 bismuth compounds?
- bismuth subsalicylate
- bismuth subcitrate potassium
Which bismuth compound?
- combination prescription product that also contains metronidazole and tetracycline for the treatment of H pylori.
bismuth subcitrate potassium
Bismuth
- Over 99% of bismuth appears where?
- What substance is (like ASA), readily absorbed and excreted in the urine
- in the stool
- Salicylate
Bismuth Compounds
- May stimulate what 3 things?
- Which bismuth reduces stool frequency and liquidity in acute infectious diarrhea?
- secretion of: prostaglandin, mucus, bicarbonate
- Bismuth subsalicylate
Bismuth has direct ____ effects against ______ and binds enterotoxins, accounting for its benefits in preventing and treating _______.
Bismuth has direct antimicrobial** against **H. pylori** and binds enterotoxins, accounting for its benefits in preventing and treating **traveler’s diarrhea.
Which bismuth is for prevention of traveler’s diarrhea?
Bismuth subsalicylate
- Which bismuth therapy is first line due to “superior compliance?”
- Which is 2nd line?
1st: “Triple Therapy”
- Proton Pump Inhibitor
- Clarithromycin
- Amoxicillin or Metronidazole
(twice daily)
2nd: Bismuth based quadruples
ADEs of Bismuth Compounds
- What are 2 harmless effects?
- Avoided in pts w/ _____ insufficiency
- Bismuth toxicity results in what?
- Bismuth toxicity is NOT reported in which 2 forms of bismuth?
- High dosages of bismuth subsalicylate can lead to what?
- 2 harmless: blackening of stool & darkening of tongue
- Avoided in pt w/ renal insufficiency
- Bismuth toxicity -> encephalopathy (ataxia, HAs, confusion, seizures)
- 2 forms bismuth toxicities NOT reported in: bismuth subsalicylate & bismuth citrate
- salicylate toxicity
ADEs of what drug?
- Nausea, Vomiting, Diarrhea
- Flatulence
- hypomagnesemia, hypocalcemia
PPI
Which drug requires monitoring of:
- Pregnancy test
- Serum phosphate
- Should avoid in pregnancy
Misoprostol
H. pylori can lead to what 2 cancers?
- Mucosa-associated lymphoid tissue (MALT) lymphoma
- Gastric cancer
What are the 4 “established indications” to treat an H. pylori infection?
- Gastric or duodenal ulcer
- MALT lymphoma
- After endoscopic resection of gastric cancer
- Uninvestigated dyspepsia
What is the triple therapy to eradicate H. pylori?
- # 1: PPI
- # 2: Clarithroymycin
- # 3: Amoxicillin or Metronidazole
(all twice daily)
What is the quadruple therapy to tx H. pylori?
- bismuth
- metronidazole
- tetracycline
- PPI
Eradication of H. pylori after abx tx may be confirmed how?
- urea breath test
- Stool antigen test
- upper endoscopy
(+ result = persistent infection)
