Upper GI Pharmacology Year 2
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Questions and Answers

What is the primary role of H. pylori urease in the stomach?

  • To kill gastric epithelial cells
  • To promote gastric acid secretion
  • To convert urea into nitrogen gas
  • To neutralize gastric acid (correct)

    • In triple therapy for H. pylori infection, which component serves as the primary treatment for acid suppression?

  • Proton pump inhibitor (correct)
  • Amoxicillin
  • Metronidazole
  • Clarithromycin

    • What is the preferred first-line therapy for a patient with H. pylori infection who is allergic to penicillin?

  • Quadruple Therapy
  • PPI and clarithromycin
  • Metronidazole and clarithromycin (correct)
  • Amoxicillin and metronidazole

    • The mechanism through which NSAIDs contribute to the development of peptic ulcers primarily involves:

    <p>Inhibition of COX and reduction of mucosal barrier function</p> Signup and view all the answers

    After completing treatment for H. pylori, when should a repeat breath test be conducted to confirm eradication?

    <p>At least two weeks after proton pump inhibitor treatment ends</p> Signup and view all the answers

    What is the primary cause of gastric ulcers?

    <p>Acid-induced damage to the mucosa</p> Signup and view all the answers

    Which of the following is NOT a common cause of peptic ulcer disease?

    <p>Increased protein intake</p> Signup and view all the answers

    What is a key component of the 'triple therapy' for treating peptic ulcers?

    <p>Antimicrobial agents, proton pump inhibitors, and H2 antagonists</p> Signup and view all the answers

    Which class of drugs can have a significant adverse effect of increasing the risk of gastrointestinal infections?

    <p>Proton pump inhibitors</p> Signup and view all the answers

    Which agent is primarily used to enhance gastrointestinal motility?

    <p>Stimulant laxatives</p> Signup and view all the answers

    What is the mechanism of action of histamine H2 antagonists?

    <p>Block histamine at H2 receptors on gastric parietal cells</p> Signup and view all the answers

    Which factor does NOT contribute to the development of peptic ulcers?

    <p>Consuming bland foods</p> Signup and view all the answers

    What is a common side effect of dopamine D2 antagonists used for nausea?

    <p>Movement disorders</p> Signup and view all the answers

    What role does K+ play in the function of the H+/K+ ATPase transporter?

    <p>It activates the transporter to secrete H+</p> Signup and view all the answers

    How do prostaglandins (PGs) such as PGE2 and PGI2 contribute to mucosal protection?

    <p>They inhibit acid secretion and promote mucus secretion</p> Signup and view all the answers

    What is the primary mechanism by which misoprostol exerts its effects in the treatment of ulcers?

    <p>Decrease acid secretion and increase mucus secretion</p> Signup and view all the answers

    Which of the following factors is considered an aggressive factor in the context of peptic ulcers?

    <p>Gastric acid</p> Signup and view all the answers

    Which of the following statements accurately reflects the pharmacological effects of sucralfate?

    <p>It forms a viscous cytoprotective gel in acid conditions.</p> Signup and view all the answers

    What is a common side effect of bismuth salts when used for gastric protection?

    <p>Reversible blackening of the tongue</p> Signup and view all the answers

    What is the physiological balance that must be maintained to prevent peptic ulcers?

    <p>Balanced gastric acid secretion and effective mucosal defense</p> Signup and view all the answers

    What is the recommended duration for the use of antacids?

    <p>No longer than 14 days without consulting a doctor</p> Signup and view all the answers

    What effect does somatostatin have on acid secretion?

    <p>It inhibits acid secretion by blocking cAMP responses</p> Signup and view all the answers

    Which cell types are involved in the synthesis of prostaglandins in the mucosal lining of the stomach?

    <p>Epithelial, endothelial, and immune cells</p> Signup and view all the answers

    Which of the following factors may decrease the bioavailability of drugs such as tetracyclines when using sucralfate?

    <p>Formation of a complex gel with the drug</p> Signup and view all the answers

    Which of the following side effects is associated with magnesium salts found in some antacids?

    <p>Diarrhea</p> Signup and view all the answers

    What is a critical mechanism for stomach mucosal protection against gastric acid?

    <p>Stimulation of mucus and bicarbonate secretion</p> Signup and view all the answers

    What role does misoprostol play in managing NSAID-induced ulcers?

    <p>It acts at prostaglandin receptors bypassing COX-2 inhibition.</p> Signup and view all the answers

    What is the primary purpose of the mucosal blood flow in the stomach?

    <p>To maintain mucosal defense</p> Signup and view all the answers

    Which enzyme is primarily responsible for the synthesis of prostaglandins from arachidonic acid?

    <p>Cyclooxygenase</p> Signup and view all the answers

    What is typically the mechanism of action of proton pump inhibitors in treating peptic ulcer disease?

    <p>Inhibit gastric acid secretion at the proton pump level</p> Signup and view all the answers

    What mechanism is involved in the cytoprotective actions of misoprostol?

    <p>Increased mucus and bicarbonate secretion</p> Signup and view all the answers

    How does a rise in pH affect D cells in the stomach?

    <p>They secrete somatostatin to inhibit acid secretion</p> Signup and view all the answers

    What type of substance is included in the composition of antacids that can specifically cause constipation?

    <p>Aluminum salts</p> Signup and view all the answers

    What is the main mechanism by which proton pump inhibitors (PPIs) exert their therapeutic effect?

    <p>Irreversibly inhibit the H+-K+ -ATPase in parietal cells</p> Signup and view all the answers

    Which of the following side effects is commonly associated with H2 receptor antagonists?

    <p>Diarrhea</p> Signup and view all the answers

    How do cytoprotective agents contribute to treating peptic ulcer disease?

    <p>By stimulating gastric mucus production and protecting ulcerated tissue</p> Signup and view all the answers

    What is a significant drug interaction concern associated with proton pump inhibitors?

    <p>Increase gastric pH and alter the absorption of drugs like Ketoconazole</p> Signup and view all the answers

    What type of drug is typically used in the treatment of gastro-oesophageal reflux disease (GERD)?

    <p>Proton pump inhibitors</p> Signup and view all the answers

    What is the primary action of H2 receptor antagonists on gastric acid secretion?

    <p>They competitively inhibit H2 receptors to reduce acid secretion.</p> Signup and view all the answers

    In the pharmacology of peptic ulcer disease, triple therapy typically includes which of the following components?

    <p>Two antibiotics and a proton pump inhibitor</p> Signup and view all the answers

    What is the role of the Cytochrome P450 system in the context of H2 receptor antagonists?

    <p>They alter the metabolism of drugs like warfarin when H2RAs are used.</p> Signup and view all the answers

    What is the bioavailability range for proton pump inhibitors following oral administration?

    <p>80-90%</p> Signup and view all the answers

    Which of the following statements characterizes the duration of action for proton pump inhibitors?

    <p>They have a long duration of action due to irreversible binding.</p> Signup and view all the answers

    What do mucus surface cells secrete?

    <p>Mucus and HCO3-</p> Signup and view all the answers

    Which of the following statements about parietal cells is correct?

    <p>Parietal cells secrete HCl.</p> Signup and view all the answers

    Which of the following statements is true regarding enteroendocrine cells found mostly in the antrum?

    <p>They secrete somatostatin and gastrin.</p> Signup and view all the answers

    What does the stretch effect on the stomach activate?

    <p>ENS – which releases ACh</p> Signup and view all the answers

    Which receptor does the Enteric Nervous System (ENS) release ACh that acts at?

    <p>Muscarinic M3 receptors</p> Signup and view all the answers

    Food particles stimulate the release of which hormone from G cells?

    <p>Gastrin</p> Signup and view all the answers

    Ach and gastrin act either directly on parietal cells, or indirectly through which mechanism?

    <p>Histamine release from ECL cells</p> Signup and view all the answers

    Histamine acts at which type of receptors to promote HCl secretion?

    <p>H2 receptors</p> Signup and view all the answers

    What happens when histamine acts at H2 receptors?

    <p>HCl concentrations increase</p> Signup and view all the answers

    Histamine, ACh, and gastrin binding to their receptors elevate levels of intracellular messengers. Which of the following are the correct messengers?

    <p>Ca2+ and cAMP</p> Signup and view all the answers

    Histamine, ACh, and gastrin binding to their receptors elevate levels of intracellular messengers, Ca2+ and cAMP. What do Ca2+ and cAMP induce?

    <p>K+ and Cl- secretion across the apical membrane</p> Signup and view all the answers

    Which statement about the role of Ca2+ and cAMP in gastric secretion is correct?

    <p>Histamine, ACh, and gastrin binding to their receptors can increase secretion of K+ and Cl- into the lumen.</p> Signup and view all the answers

    As pH rises, D cells secrete somatostatin, which inhibits acid secretion by:

    <p>blocking cAMP responses to histamine.</p> Signup and view all the answers

    Which of the following correctly describes the molecular pathway of acid secretion?

    <p>Gastrin stimulates parietal cells to secrete hydrochloric acid.</p> Signup and view all the answers

    Two important prostaglandins (PGs) produced in the stomach include:

    <p>PGE2 and PGI2</p> Signup and view all the answers

    Which of the following actions are associated with prostaglandins (PGs)? (Select all that apply)

    <p>Inhibition of acid secretion from parietal cells</p> Signup and view all the answers

    Which of the following contribute to mucosal defense? (Select all that apply)

    <p>Mucosal Blood Flow</p> Signup and view all the answers

    Which of the following are examples of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)?

    <p>Ibuprofen</p> Signup and view all the answers

    Which of the following statements about COX-1 is true? (Select all that apply)

    <p>Mediates synthesis of PGs that regulate acid and mucus secretion in the stomach</p> Signup and view all the answers

    What is the primary function of COX-2 in the body?

    <p>Mediates pain and inflammation through the synthesis of prostaglandins</p> Signup and view all the answers

    Which of the following statements about the treatment of NSAID-induced ulcers are correct? (Select all that apply)

    <p>NSAID-induced ulcers usually heal upon discontinuation of the drug</p> Signup and view all the answers

    What is the classification of Helicobacter pylori?

    <p>Gram-negative, spiral bacillus</p> Signup and view all the answers

    How does H. Pylori survive in stomach acid?

    <p>It produces an enzyme called urease</p> Signup and view all the answers

    What does urease convert urea to?

    <p>Ammonia and carbon dioxide</p> Signup and view all the answers

    How does H. pylori lead to ulceration?

    <p>Inflammation and epithelial cell death leading to loss of barrier function which allows access of acid and pepsin to the mucosa.</p> Signup and view all the answers

    What is the principle behind the Urea Breath Test? Ingests radiolabelled urea...

    <p>Urease will hydrolyze it and CO2 can be quantified in the expired breath.</p> Signup and view all the answers

    What is an example of a triple therapy used in the treatment of H. pylori infection?

    <p>Amoxicillin, clarithromycin, omeprazole</p> Signup and view all the answers

    If a patient is allergic to penicillin, what should be used in place of amoxicillin in the clarithromycin triple therapy?

    <p>Metronidazole &amp; clarithromycin</p> Signup and view all the answers

    What is the preferred 1st line of therapy for patients who have previously been treated with clarithromycin for other infections?

    <p>amoxicillin &amp; metronidazole</p> Signup and view all the answers

    If a patient is allergic to penicillin and has previously been treated with clarithromycin for other infections, what is the appropriate first line of therapy?

    <p>Use Quadruple Therapy</p> Signup and view all the answers

    Which combination of medications is most commonly used in Quadruple Therapy for Helicobacter pylori treatment?

    <p>PPI, metronidazole, tetracycline, and bismuth</p> Signup and view all the answers

    What is a common cause of heartburn?

    <p>LES does not close completely, allowing stomach acid to reflux into the esophagus.</p> Signup and view all the answers

    What can chronic heartburn lead to?

    <p>Gastroesophageal reflux disease (GERD)</p> Signup and view all the answers

    Which of the following are commonly used treatments for Gastroesophageal Reflux Disease (GERD)?

    <p>antacids, Histamine H2 antagonists, PPIs</p> Signup and view all the answers

    Which of the following medications are classified as Proton Pump Inhibitors (PPIs)? (Select all that apply)

    <p>Omeprazole</p> Signup and view all the answers

    Which statement about proton pump inhibitors (PPIs) is correct?

    <p>They irreversibly inhibit the H+-K+-ATPase.</p> Signup and view all the answers

    PPIs are prodrugs activated by acid and are converted to which of the following?

    <p>Sulfenamide which covalently binds the pump</p> Signup and view all the answers

    PPIs accumulate in which part of parietal cells?

    <p>canaliculi</p> Signup and view all the answers

    Which of the following are H2 receptor antagonists? (Select all that apply)

    <p>Cimetidine</p> Signup and view all the answers

    Which of the following statements about Histamine Receptor 2 antagonists is correct?

    <p>Reduce histamine stimulated acid secretion</p> Signup and view all the answers

    Which of the following statements about H2 receptor antagonists is true?

    <p>Peak concentrations occur 1-3 hours post administration</p> Signup and view all the answers

    Which of the following statements about Proton Pump Inhibitors (PPIs) is correct?

    <p>PPIs have a short half-life (1-2 hours)</p> Signup and view all the answers

    Which of the following statements about cytoprotective agents is correct? (Select all that apply)

    <p>They stimulate gastric mucus production and mucosal blood flow.</p> Signup and view all the answers

    MISOPROSTOL is classified as which of the following?

    <p>Cytoprotective agent</p> Signup and view all the answers

    What is true about Misoprostol?

    <p>Stable orally delivered analogue of PGE2</p> Signup and view all the answers

    MISOPROSTOL acts on which type of cells?

    <p>ECL cells</p> Signup and view all the answers

    MISOPROSTOL is good for use in NSAID-induced ulcers because:

    <p>(bypasses inhibition of COX-2 to act at PG receptors)</p> Signup and view all the answers

    SUCRALFATE is what type of medication?

    <p>Cytoprotective agent</p> Signup and view all the answers

    SUCRALFATE acts by which of the following mechanisms? (Select all that apply)

    <p>Binds to proteins in ulcerated mucosa to form a viscous cytoprotective gel</p> Signup and view all the answers

    Which statement is true regarding bismuth salt?

    <p>Given orally in a salt form, such as bismuth subsalicylate.</p> Signup and view all the answers

    Which of the following statements about Bismuth salts are correct? (Select all that apply)

    <p>Toxic against H. pylori</p> Signup and view all the answers

    What effect does BISMUTH SALT have on the body?

    <p>Reversible blackening of the tongue and faeces</p> Signup and view all the answers

    Which of the following statements about antacids is true? (Select all that apply)

    <p>Calcium, magnesium, aluminium or sodium salts</p> Signup and view all the answers

    Magnesium salts can cause which of the following effects?

    <p>Diarrhea</p> Signup and view all the answers

    What condition can aluminium-containing medications potentially cause?

    <p>Constipation</p> Signup and view all the answers

    Which of the following actions are associated with all antacids? (Select all that apply)

    <p>Hypophosphatemia</p> Signup and view all the answers

    Which of the following side effects are associated with the use of antacids? (Select all that apply)

    <p>Urinary alkalisation alters elimination of many drugs</p> Signup and view all the answers

    What are the functions and characteristics of Alginate (alginic acid)? (Select all that apply)

    <p>Anionic polysaccharide mainly found in brown algae</p> Signup and view all the answers

    Vomiting is a reflex that is under control of the?

    <p>CNS</p> Signup and view all the answers

    Control of vomiting is found in the Vomiting Centre in the......

    <p>medulla oblongata</p> Signup and view all the answers

    The Medulla Oblongata is the

    <p>most primitive area of the brain and is responsible for regulating life-sustaining involuntary bodily functions</p> Signup and view all the answers

    How does vomiting occur?

    <p>The vomiting center located in the brain stem is activated by both the PNS and SNS, causing hypo-motility and reverse-motility.</p> Signup and view all the answers

    Neural activation occurs as a result of information coming directly from the ______ of the brain, the digestive tract and balancing mechanism of the inner ear.

    <p>frontal lobes</p> Signup and view all the answers

    Anti-emetic drugs act either by:

    <p>Restoring normal gastrointestinal motility and preventing signalling through the vomiting centre</p> Signup and view all the answers

    What is the primary function of prokinetics?

    <p>Restoring normal gastrointestinal motility</p> Signup and view all the answers

    Dopamine has a direct relaxant effect on the gut by activating ...... receptors in the lower esophageal sphincter and stomach.

    <p>D2</p> Signup and view all the answers

    DA antagonists can be used to promote motility. This is an example of a:

    <p>Prokinetic</p> Signup and view all the answers

    D2 dopamine antagonist also acts as a:

    <p>5-HT4 receptor agonist</p> Signup and view all the answers

    Metoclopramide is an example of a D2 dopamine antagonist. Which of the following statements about its effects are correct? (Select all that apply)

    <p>Increases lower oesophageal sphincter tone</p> Signup and view all the answers

    Metoclopramide can also cross the blood-brain barrier (BBB) and act on which of the following?

    <p>Dopamine receptors in the chemoreceptor trigger zone</p> Signup and view all the answers

    Which of the following options is known to worsen Parkinson's symptoms?

    <p>D2 antagonists</p> Signup and view all the answers

    Which of the following statements about Domperidone are correct? (Select all that apply)

    <p>Peripheral D2 dopamine antagonist</p> Signup and view all the answers

    Which of the following medications are classified as prokinetics? (Select all that apply)

    <p>Domperidone</p> Signup and view all the answers

    Which of the following statements about anti-emetic drugs that are muscarinic antagonists is correct?

    <p>They act in the vestibular nucleus and vomiting center.</p> Signup and view all the answers

    Which of the following are muscarinic antagonists? (Select all that apply)

    <p>Hyoscine</p> Signup and view all the answers

    Which of the following statements about H1 antagonists are correct? (Select all that apply)

    <p>Act in vestibular nucleus</p> Signup and view all the answers

    Which of the following statements regarding dopamine antagonists is correct? (Select all that apply)

    <p>Act in the CTZ</p> Signup and view all the answers

    Which of the following statements about cannabinoids are correct? (Select all that apply)

    <p>Synthetic form of delta-9-</p> Signup and view all the answers

    Study Notes

    Upper GI Pharmacology Overview

    • Focus on disorders including peptic ulcer disease, gastroesophageal reflux disease, nausea, and vomiting.
    • Learning outcomes include understanding the pathophysiology, pharmacology, and treatment mechanisms.

    Peptic Ulcer Disease

    • Characterized by open sores in the stomach or duodenum.
    • Causes include NSAID usage, H. pylori infection, genetics, stress, spicy foods, and smoking.
    • Incidence: 1 in 10 individuals experience a peptic ulcer.

    Pathophysiology of Peptic Ulcers

    • A balance exists between gastric acid secretion and mucosal defense mechanisms:
      • Mucosal Defense: Mucosal blood flow, mucus, bicarbonate secretion, cell restitution, epithelial renewal.
      • Aggressive Factors: Gastric acid, pepsin, bile salts.

    Proton Pump Inhibitors (PPIs)

    • Examples: Omeprazole, esomeprazole, lansoprazole.
    • Most potent acid suppression drugs, crucial for peptic ulcer treatment, GERD, and prophylaxis against ulcers (e.g., NSAID-induced).
    • Work by irreversibly inhibiting H+-K+ ATPase, leading to decreased acid secretion.
    • Administered orally, peak action in the small intestine, high bioavailability (80-90%), long duration (48-72 hours).
    • Side effects: headache, nausea, dizziness, potential drug interactions via cytochrome P450.

    H2 Receptor Antagonists

    • Examples: Cimetidine, ranitidine, famotidine.
    • Competitively inhibit H2 receptors on parietal cells, reducing both basal and stimulated acid secretion (up to 90%).
    • Rapid oral absorption; peak concentration within 1-3 hours.
    • Side effects: diarrhea, dizziness, muscle pain, and potential interactions with drug metabolism.

    Cytoprotective Agents

    • Function to protect gastric mucosa by stimulating mucus production and increasing blood flow or coating ulcerated tissue.
    • Misoprostol: Synthetic PGE2 analogue; reduces acid secretion, increases mucus, and is effective for NSAID-induced ulcers. Side effects include diarrhea and abdominal cramps.
    • Sucralfate: Forms a protective gel upon activation in acid; binds to ulcerated mucosa and maintains mucosal blood flow. Side effects include constipation, nausea, and potential drug interactions.

    Bismuth Salts

    • Administered as bismuth subsalicylate; unclear mechanism but provides mucosal protection and exhibits toxicity against H. pylori.
    • Side effects: nausea, vomiting, and reversible discoloration of the tongue and feces.

    Antacids

    • Neutralize stomach acid using various salts (calcium, magnesium, aluminum, sodium).
    • Fast-acting (within minutes) but with a short duration of effect (30 mins to 3 hours).
    • Should not be used for more than 14 days without medical advice.
    • Side effects include diarrhea (from magnesium) and constipation (from aluminum).

    Helicobacter pylori and Peptic Ulcer Disease

    • H. pylori is a spiral Gram-negative bacillus; ~50% of the population is infected, increasing the risk of ulcers (10-20% lifetime risk for those infected).
    • Survives stomach acid by producing urease, neutralizing acid, leading to inflammation and epithelial cell death.

    Diagnostic Testing

    • Urea Breath Test: Detects active H. pylori infection; >95% sensitivity and specificity. Patient ingests radiolabeled urea; exhalation of labeled CO2 indicates infection.

    Treatment of H. pylori Infection

    • Triple Therapy (HSE recommended): Two antibiotics (amoxicillin, clarithromycin, metronidazole) plus a PPI, typically administered for 14 days.
    • Follow-up breath test two weeks after PPI completion to confirm eradication.

    HSE Recommendations for Therapy

    • Preferred first-line treatment is clarithromycin triple therapy.
    • Alternative options based on patient allergies and previous treatments:
      • Use metronidazole if allergic to penicillin.
      • Quadruple therapy as a backup (PPI, metronidazole, tetracycline, bismuth) for complex cases.

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    Description

    This quiz covers the pharmacology related to upper gastrointestinal tract disorders, including peptic ulcer disease, gastroesophageal reflux disease, and nausea and vomiting. Designed for Year 2 students at RCSI, it focuses on understanding the pathophysiology and treatment options in upper GI pharmacology.

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