Upper GI Pharmacology Year 2

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:

Inhibition of COX and reduction of mucosal barrier function Signup and view all the answers

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

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

What is the primary cause of gastric ulcers?

Acid-induced damage to the mucosa Signup and view all the answers

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

Increased protein intake Signup and view all the answers

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

Antimicrobial agents, proton pump inhibitors, and H2 antagonists Signup and view all the answers

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

Proton pump inhibitors Signup and view all the answers

Which agent is primarily used to enhance gastrointestinal motility?

Stimulant laxatives Signup and view all the answers

What is the mechanism of action of histamine H2 antagonists?

Block histamine at H2 receptors on gastric parietal cells Signup and view all the answers

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

Consuming bland foods Signup and view all the answers

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

Movement disorders Signup and view all the answers

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

It activates the transporter to secrete H+ Signup and view all the answers

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

They inhibit acid secretion and promote mucus secretion Signup and view all the answers

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

Decrease acid secretion and increase mucus secretion Signup and view all the answers

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

Gastric acid Signup and view all the answers

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

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

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

Reversible blackening of the tongue Signup and view all the answers

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

Balanced gastric acid secretion and effective mucosal defense Signup and view all the answers

What is the recommended duration for the use of antacids?

No longer than 14 days without consulting a doctor Signup and view all the answers

What effect does somatostatin have on acid secretion?

It inhibits acid secretion by blocking cAMP responses Signup and view all the answers

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

Epithelial, endothelial, and immune cells Signup and view all the answers

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

Formation of a complex gel with the drug Signup and view all the answers

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

Diarrhea Signup and view all the answers

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

Stimulation of mucus and bicarbonate secretion Signup and view all the answers

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

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

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

To maintain mucosal defense Signup and view all the answers

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

Cyclooxygenase Signup and view all the answers

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

Inhibit gastric acid secretion at the proton pump level Signup and view all the answers

What mechanism is involved in the cytoprotective actions of misoprostol?

Increased mucus and bicarbonate secretion Signup and view all the answers

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

They secrete somatostatin to inhibit acid secretion Signup and view all the answers

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

Aluminum salts Signup and view all the answers

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

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

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

Diarrhea Signup and view all the answers

How do cytoprotective agents contribute to treating peptic ulcer disease?

By stimulating gastric mucus production and protecting ulcerated tissue Signup and view all the answers

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

Increase gastric pH and alter the absorption of drugs like Ketoconazole Signup and view all the answers

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

Proton pump inhibitors Signup and view all the answers

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

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

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

Two antibiotics and a proton pump inhibitor Signup and view all the answers

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

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

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

80-90% Signup and view all the answers

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

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

What do mucus surface cells secrete?

Mucus and HCO3- Signup and view all the answers

Which of the following statements about parietal cells is correct?

Parietal cells secrete HCl. Signup and view all the answers

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

They secrete somatostatin and gastrin. Signup and view all the answers

What does the stretch effect on the stomach activate?

ENS – which releases ACh Signup and view all the answers

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

Muscarinic M3 receptors Signup and view all the answers

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

Gastrin Signup and view all the answers

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

Histamine release from ECL cells Signup and view all the answers

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

H2 receptors Signup and view all the answers

What happens when histamine acts at H2 receptors?

HCl concentrations increase 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?

Ca2+ and cAMP 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?

K+ and Cl- secretion across the apical membrane Signup and view all the answers

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

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

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

blocking cAMP responses to histamine. Signup and view all the answers

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

Gastrin stimulates parietal cells to secrete hydrochloric acid. Signup and view all the answers

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

PGE2 and PGI2 Signup and view all the answers

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

Inhibition of acid secretion from parietal cells Signup and view all the answers

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

Mucosal Blood Flow Signup and view all the answers

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

Ibuprofen Signup and view all the answers

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

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

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

Mediates pain and inflammation through the synthesis of prostaglandins Signup and view all the answers

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

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

What is the classification of Helicobacter pylori?

Gram-negative, spiral bacillus Signup and view all the answers

How does H. Pylori survive in stomach acid?

It produces an enzyme called urease Signup and view all the answers

What does urease convert urea to?

Ammonia and carbon dioxide Signup and view all the answers

How does H. pylori lead to ulceration?

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

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

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

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

Amoxicillin, clarithromycin, omeprazole 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?

Metronidazole & clarithromycin 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?

amoxicillin & metronidazole 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?

Use Quadruple Therapy Signup and view all the answers

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

PPI, metronidazole, tetracycline, and bismuth Signup and view all the answers

What is a common cause of heartburn?

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

What can chronic heartburn lead to?

Gastroesophageal reflux disease (GERD) Signup and view all the answers

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

antacids, Histamine H2 antagonists, PPIs Signup and view all the answers

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

Omeprazole Signup and view all the answers

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

They irreversibly inhibit the H+-K+-ATPase. Signup and view all the answers

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

Sulfenamide which covalently binds the pump Signup and view all the answers

PPIs accumulate in which part of parietal cells?

canaliculi Signup and view all the answers

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

Cimetidine Signup and view all the answers

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

Reduce histamine stimulated acid secretion Signup and view all the answers

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

Peak concentrations occur 1-3 hours post administration Signup and view all the answers

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

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

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

They stimulate gastric mucus production and mucosal blood flow. Signup and view all the answers

MISOPROSTOL is classified as which of the following?

Cytoprotective agent Signup and view all the answers

What is true about Misoprostol?

Stable orally delivered analogue of PGE2 Signup and view all the answers

MISOPROSTOL acts on which type of cells?

ECL cells Signup and view all the answers

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

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

SUCRALFATE is what type of medication?

Cytoprotective agent Signup and view all the answers

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

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

Which statement is true regarding bismuth salt?

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

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

Toxic against H. pylori Signup and view all the answers

What effect does BISMUTH SALT have on the body?

Reversible blackening of the tongue and faeces Signup and view all the answers

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

Calcium, magnesium, aluminium or sodium salts Signup and view all the answers

Magnesium salts can cause which of the following effects?

Diarrhea Signup and view all the answers

What condition can aluminium-containing medications potentially cause?

Constipation Signup and view all the answers

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

Hypophosphatemia Signup and view all the answers

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

Urinary alkalisation alters elimination of many drugs Signup and view all the answers

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

Anionic polysaccharide mainly found in brown algae Signup and view all the answers

Vomiting is a reflex that is under control of the?

CNS Signup and view all the answers

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

medulla oblongata Signup and view all the answers

The Medulla Oblongata is the

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

How does vomiting occur?

The vomiting center located in the brain stem is activated by both the PNS and SNS, causing hypo-motility and reverse-motility. 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.

frontal lobes Signup and view all the answers

Anti-emetic drugs act either by:

Restoring normal gastrointestinal motility and preventing signalling through the vomiting centre Signup and view all the answers

What is the primary function of prokinetics?

Restoring normal gastrointestinal motility 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.

D2 Signup and view all the answers

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

Prokinetic Signup and view all the answers

D2 dopamine antagonist also acts as a:

5-HT4 receptor agonist 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)

Increases lower oesophageal sphincter tone Signup and view all the answers

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

Dopamine receptors in the chemoreceptor trigger zone Signup and view all the answers

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

D2 antagonists Signup and view all the answers

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

Peripheral D2 dopamine antagonist Signup and view all the answers

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

Domperidone Signup and view all the answers

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

They act in the vestibular nucleus and vomiting center. Signup and view all the answers

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

Hyoscine Signup and view all the answers

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

Act in vestibular nucleus Signup and view all the answers

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

Act in the CTZ Signup and view all the answers

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

Synthetic form of delta-9- 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.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

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.