Gastric Physiology and Pharmacology Quiz

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Questions and Answers

What is the primary function of parietal cells in the stomach?

Produce hydrochloric acid (correct)

Secrete histamine

Secrete mucus

Enhance mucosal defenses

Which medication class is primarily used to reduce gastric acidity?

H2 antagonists

Antibacterials

Antacids

Proton pump inhibitors (correct)

Which of the following correctly identifies a common organism associated with peptic ulcer disease?

Escherichia coli

Staphylococcus aureus

Clostridium difficile

Helicobacter pylori (correct)

What is the pH level maintained by hydrochloric acid in the stomach?

1 to 2 Signup and view all the answers

Which statement about the action of H2 antagonists is true?

They inhibit histamine on parietal cells. Signup and view all the answers

What mechanism do H2 antagonists utilize to reduce acid secretion?

Block histamine H2 receptors Signup and view all the answers

Which of the following is an indication for using H2 antagonists?

Acid reflux Signup and view all the answers

What is one significant adverse effect of cimetidine?

Gynecomastia Signup and view all the answers

What distinguishes proton pump inhibitors (PPIs) from H2 antagonists?

PPIs irreversibly bind to the proton pump Signup and view all the answers

Which drug is not classified as a proton pump inhibitor?

Famotidine Signup and view all the answers

In the elderly, what potential adverse effect might be observed with H2 antagonists?

CNS depression Signup and view all the answers

What timing consideration should be taken when administering H2 antagonists with antacids?

Take H2 antagonists 1 hour before or after antacids Signup and view all the answers

What is the main concern regarding cimetidine's interaction with other drugs?

Inhibition of liver cytochrome P-450 Signup and view all the answers

What is a primary indication for the use of proton pump inhibitors?

GERD maintenance therapy Signup and view all the answers

Which adverse effect is commonly associated with proton pump inhibitors?

Headaches, nausea, or diarrhea Signup and view all the answers

What is a notable interaction when using proton pump inhibitors?

They can inhibit drugs requiring an acidic environment, like ketoconazole Signup and view all the answers

Which type of antacid is primarily used to counteract constipation?

Aluminum salts Signup and view all the answers

What could be a serious concern when using magnesium salts in antacids?

They can accumulate in cases of renal failure Signup and view all the answers

What is a common combination used to treat H. pylori infection?

Triple therapy of antibacterials and a proton pump inhibitor Signup and view all the answers

What precaution should be taken when using antacids concurrently with medications?

Most medications should be given 1 to 2 hours after taking an antacid Signup and view all the answers

Which statement about sucralfate is true?

It binds to ulcers and provides a protective barrier Signup and view all the answers

What is a potential side effect of calcium carbonate, a common antacid?

Constipation Signup and view all the answers

What effect does misoprostol provide in the gastrointestinal system?

It promotes mucus production and is cytoprotective Signup and view all the answers

What condition may require caution when administering sodium bicarbonate?

Chronic kidney disease Signup and view all the answers

Which of the following interactions can occur with antacids?

Chelation and reduced absorption of certain drugs Signup and view all the answers

How should omeprazole be administered?

Swallowed whole, without crushing or chewing Signup and view all the answers

Study Notes

Gastrointestinal Drugs: Peptic Ulcer Disease

This chapter covers drugs used to treat peptic ulcer disease.
Learning objectives include reviewing GI physiology, understanding the effect of hydrochloric acid, and distinguishing between different medication classes such as antacids, H2 antagonists, proton pump inhibitors, and miscellaneous acid-control agents.
The objectives also include describing the mechanism of action, indications, contraindications, interactions, and adverse effects of various drug classes.
Identifying a prototype medication, its related information, and pharmacokinetic details are included in the objectives.
Understanding client care implications is another objective.
Stomach secretions involve hydrochloric acid (HCl) from parietal cells and pepsinogen from chief cells.
Other components in the stomach include mucus, bicarbonate, and prostaglandins.

Stomach Cell Types

Parietal cells produce and secrete HCl, keeping the stomach at a pH of 1 to 2.
They are the primary target for acid-controller drugs.
ECL cells secrete histamine, stimulating parietal cells.

Acidity affects the integrity of the digestive tract.
Common stomach problems include indigestion, heartburn, and acid stomach.
Peptic ulcer disease (PUD) and gastroesophageal reflux disease (GERD) are mentioned.
Common locations of gastric and duodenal ulcers are illustrated.

Factors in Peptic Ulcer Disease

Aggressive factors such as H. pylori infection, NSAIDs, acid, pepsin, and smoking contribute to ulcers.
Defensive factors such as mucus, bicarbonate, blood flow, and prostaglandins protect the stomach lining.

Drug Therapies for H. Pylori

Eradication of H. pylori, reduction of gastric acidity, and enhancement of mucosal defenses are important aspects of treatment.
Antibacterials like amoxicillin and clarithromycin are used in triple therapy for H. pylori eradication along with a proton pump inhibitor like omeprazole. This regimen is typically for seven to 14 days.

Inhibitors of Gastric Acid Secretion/Action

H2 antagonists, proton pump inhibitors, and antacids are discussed.
Different types of antacids include magnesium salts, calcium salts, sodium bicarbonate, and aluminum salts.
Other agents, such as sucralfate and misoprostol, protect the mucosa.

H2 Antagonists:

Reduce acid secretion, and are available in OTC lower dosages.
Cimetidine (Tagamet), famotidine (Pepcid), ranitidine (Zantac), and nizatidine (Axid) are examples.
Cimetidine may interact with other drugs, affecting their metabolism.
Care is needed in patients with impaired renal or liver function, confusion, disorientation, or in the elderly.
H2 antagonists block histamine H2 receptors that stimulate acid-producing parietal cells.
Indications include GERD, PUD, adjunct therapy for upper GI bleeding and hypersecretory conditions.
Adverse effects are infrequent but cimetidine can cause impotence and gynecomastia. Older patients may experience CNS depression (e.g., lethargy) or confusion.

Proton Pump Inhibitors (PPIs):

Inhibit the pump that moves H+ into the stomach lumen, making them more effective than H2 antagonists.
Omeprazole (Losec or Prilosec), lansoprazole, rabeprazole, pantoprazole (Pantoloc), and esomeprazole are examples.
PPIs irreversibly bind to the H+/K+ ATPase enzyme.
They are used for GERD maintenance therapy, erosive esophagitis, short-term treatment of active duodenal and benign gastric ulcers, and Zollinger-Ellison syndrome.
PPIs are generally safe for short-term use (4-8 weeks). Headaches, GI problems (nausea, vomiting, diarrhea) are uncommon side effects. Caution is advised in patients with liver disease.

Antacids:

Chemically neutralize stomach acid; they do not prevent acid production.
Common forms include capsules, tablets, powders, and suspensions.
Types of antacids include aluminum, magnesium, calcium salts, and sodium bicarbonate.
Aluminum salts can cause constipation; Magnesium salts often cause diarrhea; calcium salts can cause constipation and possible kidney stones.
Sodium bicarbonate is highly soluble but short-lasting and may cause metabolic alkalosis, so it is not recommended to clients with fluid imbalances, hypertension, HF, renal insufficiency and preexisiting conditions.
Antacids may reduce the absorption of other medications if taken close to each other.
Patients with allergies, fluid imbalances, renal issues, pregnancy, or GI obstructions should be evaluated carefully before taking antacids.
Patients should follow instructions on timing relative to other medications.

Other Agents to Protect the Mucosa:

Sucralfate binds directly to ulcer surfaces, forming a protective barrier and inhibiting pepsin.
Sucralfate may have minimal absorption, but can cause constipation, nausea, and dry mouth. It may also impair the absorption of other drugs, such as tetracycline and digoxin, or it might interfere with phosphate levels.
Misoprostol is a synthetic prostaglandin used to reduce gastric effects of NSAIDs; it may cause abdominal cramps and diarrhea.

Client Care Guidelines:

Patient history is imperative for proper treatment planning. Assessment for allergies and pre-existing conditions such as fluid imbalances, renal or liver disease, HF, pregnancy, and GI obstructions must be considered.
Clients with heart failure (HF) or hypertension should consider low-sodium antacids.
Medications are often best taken one to two hours after antacids to prevent drug interactions.
Chewable tablets should be chewed completely.
Patients taking omeprazole should be instructed not to crush, chew, or open the capsule.
Antacids may be taken with water to enhance dispersion but not if rapid-dissolving forms are utilized.
Caffeine, alcohol, harsh spices, and black pepper may worsen underlying GI conditions.
Inform clients that treatment duration is often limited to a short term, for example several weeks rather than a long term or permanent solution.

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Description

Test your knowledge on the primary functions of gastric cells and the medications used to manage acidity. This quiz covers key concepts such as the role of parietal cells, common organisms linked to peptic ulcers, and the action of H2 antagonists. Improve your understanding of gastric physiology and pharmacology.