GI Disorders and Treatment Overview

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Questions and Answers

What is a significant contraindication for the use of H2 antagonists?

Known allergy (correct)

Occasional heartburn

Mild headaches

Age over 65

Which of the following adverse effects is associated with H2 antagonists?

Hypertension

Gynecomastia (correct)

Dry mouth

Severe weight loss

In which population should H2 antagonists be used with caution?

Children older than 12

Patients undergoing surgery

Individuals with a high tolerance to medication

Pregnant patients (correct)

Which H2 antagonist is known to slow the metabolism of various drugs?

Cimetidine Signup and view all the answers

What is a common GI-related adverse effect of H2 antagonists?

Nausea Signup and view all the answers

What is the main therapeutic action of Histamine-2 (H2) antagonists?

Block H2 receptors to reduce hydrochloric acid release Signup and view all the answers

Which drug class is used for the treatment of erosive GERD?

Histamine-2 antagonists Signup and view all the answers

What condition is NOT indicated for the use of H2 antagonists?

Acid reflux unrelated to ulcers Signup and view all the answers

Which of the following is a common side effect of drugs affecting gastrointestinal secretions?

Nausea and vomiting Signup and view all the answers

What is one of the primary roles of antacids?

Neutralize gastric acidity Signup and view all the answers

Which agent blocks gastric secretions and forms protective coverings on the GI lining?

Gastrointestinal protectants Signup and view all the answers

Which of the following is a reason for the withdrawal of ranitidine from the market?

Concerns over impurities and safety Signup and view all the answers

What is a common underlying cause of GI disorders?

Dietary excess Signup and view all the answers

Which interaction may lead to decreased serum levels and effectiveness of the drug?

Warfarin and sucralfate Signup and view all the answers

What is a therapeutic action of synthetic prostaglandin E1 analogue misoprostol?

Inhibits gastric acid secretion Signup and view all the answers

What condition is misoprostol primarily indicated for?

Prevention of NSAID-induced gastric ulcers Signup and view all the answers

What is a primary adverse effect associated with prostaglandins?

GI-related effects Signup and view all the answers

Which of the following represents a caution when using a saliva substitute?

Renal failure Signup and view all the answers

What is the mechanism of action for pancreatic enzymes like pancrelipase?

Helps digest fats, proteins, and carbohydrates Signup and view all the answers

What is a potential adverse effect of pancreatic enzyme replacement therapy?

GI irritation Signup and view all the answers

What is one contraindication for using misoprostol?

Pregnancy Signup and view all the answers

Which of the following digestive enzymes is specifically a saliva substitute?

Aquoral Signup and view all the answers

What common effect is associated with the use of a saliva substitute?

Thickening agent for food bolus Signup and view all the answers

What is the main therapeutic action of antacids?

Neutralize stomach acid Signup and view all the answers

Which of the following is a common adverse effect associated with the use of antacids?

Alkalosis Signup and view all the answers

What is the primary indication for proton pump inhibitors?

Treatment of erosive esophagitis Signup and view all the answers

Which drug is classified as a proton pump inhibitor?

Omeprazole Signup and view all the answers

What condition is a contraindication for the use of proton pump inhibitors?

Allergy to the medication Signup and view all the answers

What is a significant caution associated with the use of GI protectants?

Renal failure Signup and view all the answers

Which adverse effect is most frequently seen with GI protectants?

Constipation Signup and view all the answers

Which type of imbalance can antacids potentially exacerbate?

Electrolyte or acid-base imbalance Signup and view all the answers

What is one of the therapeutic actions of proton pump inhibitors?

Inhibit the H+, K+–ATPase enzyme system Signup and view all the answers

Which of the following drugs interacts with proton pump inhibitors?

Warfarin Signup and view all the answers

Which patient condition warrants caution when prescribing antacids?

Electrolyte imbalance Signup and view all the answers

What is the mechanism through which GI protectants promote healing?

Coating injured areas to prevent further injury Signup and view all the answers

What is the excretion route for GI protectants after absorption?

Primarily excreted via feces Signup and view all the answers

What is a potential outcome of frequent antacid use?

Acid rebound Signup and view all the answers

Study Notes

Underlying Causes of GI Disorders

Dietary excess, stress, hiatal hernia, GERD, peptic ulcer disease, and adverse drug effects can all contribute to GI disorders

GERD and Ulcer Disease

Medications can be used to lessen GI secretions, block the action of GI secretions or form a protective covering on the GI lining to prevent erosion
Common drug classes for GERD and ulcer disease treatment include histamine-2 agonists, antacids, proton pump inhibitors, gastrointestinal protectants, and prostaglandins

Histamine-2 (H2) Antagonists

Block the release of hydrochloric acid in response to gastrin
Cimetidine (Tagamet HB), Famotidine (Pepcid AC), Nizatidine (Axid AR), and Ranitidine (Zantac) are available OTC
Ranitidine (Zantac) was withdrawn from the market
H2 agonists block H2 receptors and prevent about 70% of hydrochloric acid release
H2 agonists also decrease pepsin production

Indications for H2 Antagonists

Short-term treatment of active duodenal or gastric ulcers, treatment of Zollinger–Ellison syndrome, prophylaxis of stress or NSAID-induced ulcers or acute upper GI bleeding, treatment of erosive GERD, treatment of H. pylori ulcers, relief of heartburn and indigestion are all indications for H2 antagonist use

Pharmacokinetics of H2 Antagonists

The pharmacokinetics of H2 antagonists vary by drug
H2 Antagonists cross the placenta and enter the human milk

Contraindications and Cautions for H2 Antagonists

Patients with known allergy to H2 antagonists should avoid these drugs
Caution should be used with pregnancy or lactation, hepatic or renal dysfunction, and with extended or continual use

Adverse Effects and Drug Interactions of H2 Antagonists

GI effects, CNS effects, cardiac arrhythmias, hypotension, gynecomastia, and impotence are all possible adverse effects of H2 antagonists
Cimetidine slows metabolism of other drugs and there are reported drug-drug interactions with nizatidine and aspirin

Antacids

Antacids are a group of inorganic chemicals that neutralize stomach acid
Antacids are often used OTC for a variety of symptoms
Sodium bicarbonate (generic), Calcium carbonate (Oystercal, Tums), Magnesium salts (Milk of Magnesia), and Aluminum salts (Amphojel) all have similar effects on the stomach

Therapeutic Actions and Indications of Antacids

Antacids neutralize stomach acid by direct chemical reactions
These drugs are indicated for symptomatic relief of upset stomachs, hyperactivity, relief of symptoms associated with hyperactivity, peptic ulcers, gastritis, etc.

Pharmacokinetics, Contraindications, and Cautions for Antacids

Antacids vary by drug in terms of their pharmacokinetics
Patients allergic to antacids should avoid the use of these drugs
Antacids should be used cautiously for patients with any conditions that could be worsened by electrolyte or acid-base imbalance, electrolyte imbalance, GI obstruction, renal dysfunction, and in pregnant and lactating women

Adverse Effects and Drug Interactions of Antacids

Antacids can have adverse effects on acid-base and electrolyte balance
Common adverse effects include rebound acidity, alkalosis, hypercalcemia, constipation or diarrhea, and hypophosphatemia
Antacids can affect the absorption of other drugs

Proton Pump Inhibitors

Proton pump inhibitors suppress the secretion of hydrochloric acid into the lumen of the stomach
Omeprazole (Prilosec), Esomeprazole (Nexium), Lansoprazole (Prevacid), Dexlansoprazole (Dexilant), Pantoprazole (Protonix), and Rabeprazole (Aciphex) are all commonly prescribed proton pump inhibitors

Therapeutic Action and Indications of Proton Pump Inhibitors

Proton Pump inhibitors specifically inhibit the H+, K+–ATPase enzyme system on the gastric parietal cells
Proton Pump inhibitors block the final step of acid production
Proton pump inhibitors are indicated for the short-term treatment of active duodenal ulcers, GERD, erosive esophagitis, and benign active gastric disease
Long-term treatment of pathological hypersecretory conditions, as well as maintenance therapy for erosive esophagitis and ulcers are also indications for these drugs

Pharmacokinetics, Contraindications, and Cautions of Proton Pump Inhibitors

Proton Pump inhibitors are acid labile, rapidly absorbed from the GI tract
These drugs are metabolized in the liver and excreted in the urine
Patients with allergies to proton pump inhibitors should avoid these drugs
The concurrent use of proton pump inhibitors and medications containing rilpivirine should be avoided
Caution should be exercised when prescribing these medications to pregnant and lactating women

Adverse Effects and Drug Interactions of Proton Pump Inhibitors

Adverse effects are typically related to effects on the H+, K+–ATPase pump on parietal and other cells
Possible adverse effects include CNS effects, GI effects, upper respiratory tract symptoms, and other less common effects
Long-term use can lead to increased bone loss and hypertension
Drug-Drug interactions can occur with benzodiazepines, phenytoin, warfarin, ketoconazole, theophylline, and some antiretroviral medications

Gastrointestinal Protectant

Sucralfate (Carafate) coats any injured area of the stomach to prevent further damage from acid

Therapeutic Actions and Indications for Gastrointestinal protectants

Gastrointestinal protectants form an ulcer-adherent complex at duodenal ulcer sites protecting the sites against acid, pepsin, and bile salts
Gastrointestinal protectants prevent further breakdown and promote healing
Gastrointestinal protectants inhibit pepsin activity in gastric juices
Gastrointestinal protectants are indicated for the treatment of ulcers

Pharmacokinetics, Contraindications, and Cautions for Gastrointestinal Protectants

Gastrointestinal protectants are minimally absorbed
Most are excreted via feces; small amounts absorbed are excreted in the urine

Adverse Effects and Drug Interactions of Gastrointestinal Protectants

Adverse effects are primarily GI related, with constipation the most common side effect
Other less common effects are dizziness, sleepiness, vertigo, skin rash, and back pain
Drug-drug interactions can occur with aluminum salts, phenytoin, digoxin, warfarin, fluoroquinolone antibiotics, or penicillamine

Prostaglandins

Misoprostol (Cytotec) is a synthetic prostaglandin E1 analogue that protects the stomach lining

Therapeutic Actions and Indications for Prostaglandin

Prostaglandins inhibit gastric acid secretion
Prostaglandins increase the bicarbonate and mucous production in the stomach
Prostaglandin is indicated for the prevention of NSAID-induced gastric ulcers in patients at high risk for complications

Pharmacokinetics, Contraindications, and Cautions for Prostaglandins

Prostaglandins are rapidly absorbed from the GI tract
Prostaglandins are metabolized in the liver and excreted in the urine
Prostaglandins cross the placenta and enter human milk

Adverse Effects and Drug Interactions of Prostaglandins

Adverse effects are primarily related to GI effects
GU effects are also reported

Digestive Enzymes

Digestive enzymes are produced in the GI tract to break down foods into usable nutrients
Saliva substitutes (Aquoral, Moi-Stir, Mouth Kote, Salivart) and Pancrelipase (Creon, Pancreaze, Pertzye, Viokace, Zenpep) are the two main digestive enzymes used therapeutically

Therapeutic Actions and Indications for Digestive Enzymes

Saliva substitute contains electrolytes and carboxymethylcellulose to act as a thickening agent in dry mouth conditions
Saliva substitutes help make the food bolus easier to swallow
Pancreas enzymes are replacement enzymes that help with the digestion and absorption of fats, proteins, and carbohydrates
Digestive enzymes are indicated for replacement therapy

Pharmacokinetics, Contraindications, and Cautions for Digestive Enzymes

Saliva substitutes are not generally absorbed systemically
Saliva substitutes work when topically applied to the mouth
Pancrelipase is thought to be processed through typical metabolic systems
Patients with allergies to digestive enzymes should avoid these drugs
Caution should be used with saliva substitutes in patients with HF, hypertension, or renal failure

Adverse Effects of Digestive Enzymes

Saliva substitute complications arise from abnormal electrolyte absorption
Pancreatic enzymes are associated with GI irritation such as nausea, abdominal cramps, and diarrhea

Question #1

Famotidine is available in both oral and parenteral forms
Nizatidine and cimetidine are only available in oral forms
Lansoprazole is available in both oral and parenteral forms but is a proton pump inhibitor

Question # 2

True
Sucralfate can interact with phenytoin, digoxin, warfarin, fluoroquinolone antibiotics (e.g., ciprofloxacin, norfloxacin), or penicillamine

Question # 3

Cimetidine (Tagamet HB) has been associated with antiandrogenic effects

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Description

This quiz covers the underlying causes of gastrointestinal (GI) disorders, including dietary and medication influences. It also explores the role of H2 antagonists in managing conditions like GERD and peptic ulcer disease. Learn about different drug classes and their mechanisms in treating GI issues.