Pharm Final

A client has just been diagnosed with peptic ulcer disease. What first-choice drug does the nurse anticipate will be prescribed for this client? 1. Famotidine (Pepcid) 2. Magaldrate (Riopan) 3. Omeprazole (Prilosec) 4. Sodium bicarbonate (Alka-Seltzer)

1 Rationale 1: H2-receptor blockers are the drugs of first choice in treating peptic ulcers. Rationale 2: Magaldrate (Riopan) is incorrect because Alka-Seltzer and Riopan are antacids. Rationale 3: Omeprazole (Prilosec) is incorrect because Prilosec is a proton pump inhibitor. Rationale 4: Sodium bicarbonate (Alka-Seltzer) is incorrect because Alka-Seltzer and Riopan are antacids. Global Rationale: H2-receptor blockers are the drugs of first choice in treating peptic ulcers. Magaldrate (Riopan) is incorrect because Alka-Seltzer and Riopan are antacids. Omeprazole (Prilosec) is incorrect because Prilosec is a proton pump inhibitor. Sodium bicarbonate (Alka-Seltzer) is incorrect because Alka-Seltzer and Riopan are antacids.

The nurse is teaching a patient who has a diagnosis of diabetes mellitus type 2 about a new prescription for glyburide (DiaBeta). The nurse knows the patient understands teaching when the patient states, "I need to monitor for dizziness, lightheadedness, and sweating if I take Standard Text: Select all that apply. 1. ibuprophen (Motrin) for pain." 2. ranitidine (Zantac) for heartburn." 3. cetirizine (Zyrtec) for allergies." 4. metoprolol (Lopressor) for hypertension." 5. docusate sodium (Colace) for constipation."

1,2,4 -- Dizziness, lightheadedness, and sweating are symptoms of hypoglycemia. Monitor for hypoglycemia if the patient is also taking nonsteroidal anti-inflammatory agents (NSAIDs), sulfonamide antibiotics, ranitidine, cimetidine, or beta blockers; these drugs intensify the action of sulfonylureas.

The nurse is reviewing the medication administration record for a client who is receiving an initial regimen for the eradication of H. pylori. The nurse anticipates the inclusion of which medications for this client? Note: Credit will be given only if all correct choices and no incorrect choices are selected. Standard Text: Select all that apply. 1. Omeprazole 2. Metronidazole 3. Bismuth subsalicylate 4. Amoxicillin 5. Clarithromycin

1,4,5 Rationale 1: Omeprazole is a medication included in the initial medication regimen in the eradication of H. pylori. Rationale 2: Metronidazole is not included in the initial medication regimen in the eradication of H. pylori. Rationale 3: Bismuth subsalicylate is not included in the initial medication regimen in the eradication of H. pylori. Rationale 4: Amoxicillin is a medication included in the initial medication regimen in the eradication of H. pylori. Rationale 5: Clarithromycin is a medication included in the initial medication regimen in the eradication of H. pylori.

The nurse is caring for a teenager with PUD. The nurse recommends that client begin taking ranitidine (Zantac) OTC because the client is older than ____ year(s). Standard Text: Record your answer rounding to the nearest whole number.

12 Rationale: OTC administration of ranitidine is contraindicated in children younger than 12 years of age. Children older than 12 years, however, may be prescribed the medication for the treatment of PUD OTC.

A client is prescribed omeprazole, bismuth subsalicylate, and metronidazole for the treatment of H. pylori. The nurse explains that combination therapy will accomplish which outcome? 1. Increase the number of ulcerations 2. Eliminate the population of H. pylori 3. Allow H. pylori to adhere to the gastric mucosa 4. Immediately relieve symptoms of gastric ulceration

2 Rationale 1: A goal of combination therapy is not to increase the number of ulcerations. Rationale 2: A goal of combination therapy is to eliminate the population of H. pylori. Rationale 3: Combination therapy will inhibit bacterial growth by disrupting their cell wall and preventing H. pylori from adhering to the gastric mucosa. Rationale 4: The goal of combination therapy is to eradicate H. pylori and heal ulcerations. Symptoms will not immediately be relieved by this therapy.

A client is prescribed omeprazole (Prilosec). The nurse prepares to perform client teaching based on the knowledge that omeprazole is a: 1. nicotinic receptor blocker. 2. proton pump inhibitor. 3. muscarinic receptor blocker. 4. histamine-2 receptor agonist.

2 Rationale 1: Omeprazole is not a nicotinic receptor blocker. Rationale 2: Omeprazole is a proton pump inhibitor. Rationale 3: Omeprazole is not a muscarinic receptor blocker. Rationale 4: Omeprazole is not a histamine-2 receptor blocker.

An adult client who prescribed the anticholinergic oxybutynin (Ditropan) for urinary incontinence is admitted to the unit with acute muscle spasms after twisting her back in a fall. Which medication used for muscle spasm relaxation would cause the nurse the most concern? 1. Ibuprofen 600 mg 2. Cyclobenzaprine (Flexeril) 3. Tizanidine (Zanaflex) 4. Chlorzoxazone (Parafon Forte)

2 Rationale 1: There is no contraindication for use of ibuprofen with anticholinergics. Rationale 2: Cyclobenzaprine will enhance anticholinergic side effects and is contraindicated with anticholinergics. Rationale 3: There is no contraindication for use of tizanidine with anticholinergics. Rationale 4: There is no contraindication for use of chlorzoxazone with anticholinergics.

A client in a long-term care facility is ordered to receive ranitidine (Zantac). When should the nurse administer this medication? 1. At bedtime with water 2. After the evening meal 3. Before eating in the morning 4. One hour before meals

2 Rationale 1: Unless otherwise indicated, the drug should not be taken at bedtime. Rationale 2: The ideal time to administer ranitidine is after the evening meal, as the buffering effect of food can increase the therapeutic effect. Rationale 3: Unless otherwise indicated, the drug should not be taken on an empty stomach. Rationale 4: Unless otherwise indicated, the drug should not be taken before meals.

The nurse is discharging an older adult client who was hospitalized after a muscle strain injury to his back. One of the discharge prescriptions for this client is cyclobenzaprine (Flexeril) 10 mg three times per day with food. The prescription is written for 90 tablets and there are three refills available. Which information from this situation would alert the nurse for the need to collaborate with the client's health care provider? Note: Credit will be given only if all correct choices and no incorrect choices are selected. Standard Text: Select all that apply. 1. The dosage amount is too low for the type of injury this client sustained. 2. Cyclobenzaprine should be used with great caution in those over 65. 3. If taken as directed, the client would be able to take the medication for 120 days. 4. Cyclobenzaprine is not effective for back pain. 5. Cyclobenzaprine should not be taken with food.

2,3 Rationale 1: The dosage of 10 mg three times daily is standard. Rationale 2: The adverse reactions from cyclobenzaprine include confusion, hallucinations, and cardiac events, which are more common in clients over 65. Rationale 3: The manufacturer recommends that treatment not extend beyond 3 weeks or 21 days. Rationale 4: Cyclobenzaprine is not effective for muscle spasm due to spinal cord injury, but is useful in the treatment of back pain from muscle strain. Rationale 5: The drug may be taken with food or milk if gastric upset occurs.

A client was placed on ranitidine (Zantac) 2 days ago, and continues to complain of ulcer pain. What is the best response by the nurse? 1. "We'll switch you to a different medication." 2. "You probably have something else besides an ulcer." 3. "You might not notice relief for several days." 4. "You should be taking the medication with food."

3 Rationale 1: "We'll switch you to a different medication" is incorrect because switching to a different medication would be premature at this point. Rationale 2: "You probably have something else besides an ulcer" is incorrect because diagnosing another condition is outside the scope of nursing practice. Rationale 3: Patients should be advised that it can take several days of therapy before they gain relief from ulcer pain. Beneficial effects last 3-5 days after therapy is stopped. Rationale 4: "You should be taking the medication with food" is incorrect because the medication can be taken with or without food. Global Rationale: Patients should be advised that it can take several days of therapy before they gain relief from ulcer pain. Beneficial effects last 3—5 days after therapy is stopped. "We'll switch you to a different medication" is incorrect because switching to a different medication would be premature at this point. "You probably have something else besides an ulcer" is incorrect because diagnosing another condition is outside the scope of nursing practice. "You should be taking the medication with food" is incorrect because the medication can be taken with or without food.

A client who was discontinued from using an MAOI 1 week ago has injured his back and is in pain from severe muscle spasms. The client is prescribed cyclobenzaprine (Flexeril) for the muscle spasms. Which nursing action is the most important? 1. Inform the client to watch for added CNS depression. 2. Warn the client not to operate a motorized vehicle until the effects of the medication are known. 3. Hold the Flexeril and notify the health care provider. 4. Give the Flexeril as prescribed.

3 Rationale 1: Added CNS depression is not the important concern here. Rationale 2: Although the client should not operate a motorized vehicle until effects of the drug are known, this is not the most important issue. Rationale 3: A potentially fatal hypertensive crisis could occur if cyclobenzaprine is used within 14 days of an MAOI. Rationale 4: The health care provider needs to be notified that the client has not been off the MAOI for the required minimum of 14 days before the Flexeril was prescribed.

A client with a diagnosis of peptic ulcer disease is prescribed omeprazole (Prilosec) and asks the nurse where in the body this medication will work. The nurse correctly answers: 1. "On the gastric mucus layer." 2. "On the mucosa of the trachea." 3. "On the surface of parietal cells." 4. "On the H2 receptors."

3 Rationale 1: Omeprazole is a proton pump inhibitor and works on the proton pump, which is located on the surface of parietal cells. Rationale 2: Omeprazole is a proton pump inhibitor and works on the proton pump, which is located on the surface of parietal cells. Rationale 3: Omeprazole is a proton pump inhibitor and works on the proton pump, which is located on the surface of parietal cells. Rationale 4: H2-receptor antagonists work on H2 blockers. Omeprazole is a proton pump inhibitor and works on the proton pump, which is located on the surface of parietal cells.

Which instruction is most appropriate for a client who is prescribed pancrelipase (Cotazym)? 1. Increase dosing with a large meal. 2. Decrease fluid intake. 3. Take the medication at least 2 hours prior to meals. 4. Take the medication with meals

4 Rationale 1: Increase dosing with a large meal is incorrect because overtreatment can cause nausea, vomiting, and diarrhea. Rationale 2: Decrease fluid intake is incorrect because this is not necessary with this medication. Rationale 3: Decrease fluid intake is incorrect because this is not necessary with this medication. Rationale 4: Dosing is individualized to the degree of pancreatic insufficiency in each patient. Administration of the drug is timed to coincide with meals so that the enzymes are available when food reaches the duodenum.

The nurse is caring for a client who is prescribed cyclobenzaprine (Flexeril) for lower back pain following a work injury. The client has been quite drowsy, and dozes off and on throughout the day while taking the Flexeril. Which action by the nurse is the most appropriate for this client? 1. Notifying the health care provider that the client is experiencing extreme drowsiness 2. Providing the client caffeinated beverages to help the client stay awake 3. Holding the cyclobenzaprine until the client can be further evaluated 4. Continuing the medication as ordered

4 Rationale 1: Skeletal muscle relaxants, such as Flexeril, act on the CNS and produce sedation, which helps the client with muscle spasms to sleep. Rationale 2: It is the sedative effect of the centrally acting muscle relaxants that helps the muscle spasms. Rationale 3: There is no need to hold the medication, as the sedative effect is expected. Rationale 4: Continue the medication as ordered. Centrally acting muscle relaxants work through their sedating effects.

A client is prescribed ranitidine (Zantac). The nurse checks the client's BUN and serum creatinine levels prior to administering the drug for the first time. The rationale for checking these labs is: 1. serum BUN and creatinine should be checked on all clients. 2. that the drug is primarily biometabolized by the liver. 3. to identify a hidden drug allergy. 4. that the drug is primarily excreted by the kidneys.

4 Rationale 1: Serum creatinine and BUN do not need to be checked on all clients. Rationale 2: Serum creatinine and BUN do not measure liver function. Rationale 3: Serum creatinine and BUN will not identify hidden drug allergies. Rationale 4: These drugs are mainly excreted by the kidneys, and clients with diminished kidney function require smaller doses.

A patient who is prescribed omeprazole (Prilosec) asks the nurse why the drug should be taken before breakfast. What is the nurse's best response? a. "The intended action of this drug is best achieved when given before meals, preferably in the morning." b. "It is best to take this drug in the morning so that antacids taken later in the day do not interfere with absorption." c. "This drug should always be taken on an empty stomach for maximal action and for better absorption." d. "Taking this drug early in the morning helps to minimize the occurrence of side effects or adverse effects."

A Omeprazole is a proton pump inhibitor. These drugs work best when given before meals, preferably in the morning. Proton pump inhibitors can be given with antacids, with food, or without food.

A client with a gastric ulcer and Helicobacter pylori infection is being treated with triple therapy (bismuth, metronidazole, and amoxicillin) and ranitidine (Zantac). The client asks why ranitidine is necessary, because the triple therapy will treat the cause of the ulcer. What is the nurse's best response? A. "Ranitidine will help to heal the ulcer and prevent recurrence." B. "Ranitidine is a potent antibiotic used to eliminate H. pylori infection." C. "Ranitidine dissolves in the stomach and coats the ulcer so it will heal faster." D. "Ranitidine will help control diarrhea that can result from the triple therapy."

A Used in conjunction with triple therapy for the treatment of H. pylori-induced ulcers, ranitidine will help heal the ulcer and prevent recurrence.

A client is with a history of gastroesophageal reflux disorder (GERD) presents with metabolic alkalosis. Based on the data reviewed in the client's history, which medication does the nurse suspect contributed to the current diagnosis? A) Omeprazole B) Ranitidine C) Aluminum hydroxide D) Metoclopramide

C.

The nurse is providing care to an older adult client admitted to the medical unit for acute gastric and left upper abdominal pain radiating to the back. The healthcare provider has diagnosed the client with chronic pancreatitis. Which items are appropriate to include in the discharge teaching for this client? Select all that apply. A) Eliminating alcoholic beverages B) Monitoring weight every week C) Properly administering pancrelipase D) Taking antacids E) Encouraging a high-fat diet

A, B, C

A client with severe GERD is still having symptoms of reflux despite taking omeprazole (Prilosec) 20 mg daily. What is the nurse's best action? A. Document the finding as the only action. B. Notify the health care provider. C. Instruct the client to stop the medication immediately. D. Instruct the client to take an antacid in addition to the omeprazole.

B Omeprazole is a proton pump inhibitor that acts to reduce gastric acid secretion. If once-daily dosing fails to control the client's symptoms, the nurse should notify the health care provider, because the dose can be increased to twice daily for better symptom control.

A patient with an inflammatory response is prescribed ranitidine (Zantac) 75 mg once a day. What is the nurse's best action? a. Give the drug as ordered. b. Hold the drug and notify the prescriber. c. Teach the patient to take the drug first thing in the morning. d. Ask the patient if he or she is allergic to any drugs or other substances.

B Ranitidine (Zantac) is an H2 receptor blocker used to decrease production of stomach acids. The prescriber has confused this drug with cetirizine (Zyrtec), an H1 receptor blocker used to slow or stop tissue effects of inflammation.

A patient is prescribed omeprazole (Prilosec) 60 mg once a day orally. The patient is having difficulty with swallowing and has a feeding tube in place. What is the nurse's best action? a. Open the capsule and mix the contents with water, then give the drug through the feeding tube. b. Raise the head of the bed 90 degrees and mix the capsule in applesauce for easier swallowing. c. Contact the prescriber and pharmacist about using another drug or another form of the drug. d. Hold the tube feeding for at least 30 minutes before giving the drug.

C Omeprazole comes in time-released capsules, which should not be opened to prevent rapid absorption of the drug and consequent side effects or adverse effects. Mixing the drug with applesauce and asking the patient to swallow it when the patient has difficulty swallowing puts the patient at high risk for aspiration.

A patient who has been prescribed ranitidine (Zantac) reports darkened stools. What is the nurse's best action? a. Hold the dose and notify the prescriber. b. Document the report as the only action. c. Reassure the patient that this is a common and harmless side effect. d. Ask the patient if he or she has been using aspirin or any other nonsteroidal anti-inflammatory drug (NSAID).

C Ranitidine contains a substance that darkens the tongue and the stools. This is a harmless side effect and does not indicate a health problem. It is not a reason to stop the drug.

A histamine-receptor antagonist such as cimetidine (Tagamet) or ranitidine (Zantac) is ordered for an infant with GER. The purpose of this is to: a. prevent reflux. b. prevent hematemesis. c. reduce gastric acid production. d. increase gastric acid production.

C The mechanism of action of histamine-receptor antagonists is to reduce the amount of acid present in gastric contents and perhaps prevent esophagitis. Preventing reflux or hematemesis and increasing gastric acid production are not the modes of action of histamine-receptor antagonists.

A patient with gastroesophageal reflux disease is prescribed ranitidine (Zantac). Which statement by the patient indicates to the nurse a need for additional teaching? a. "If I need to use ranitidine for more than 2 weeks, I will notify my prescriber." b. "I will look into a smoking cessation program when I go home." c. "I will take the ranitidine first thing in the morning so that its effect will last all day and night." d. "I will not drive until I know how the ranitidine affects me."

C To prolong the effects of histamine H2 blockers like ranitidine, they should be taken with meals. If a patient takes this drug once a day, giving it at bedtime prolongs the effects when there is no food in the stomach and reflux may be worse.

Which of the following medications does NOT interfere with the blood-clotting process? A) Warfarin B) Clopidogrel C) Heparin D) Omeprazole

D.

Which of the following medications for treating allergic reactions and anaphylaxis also relieves the abdominal cramping associated with both? A) Epinephrine B) Ranitidine C) Dopamine D) Diphenhydramine

D.

The nurse would expect to see an order for a drug that blocks H2 receptors in a client with: 1. excess gastric acid production. 2. peptic ulcer disease. 3. gastroesophageal reflux disease. 4. allergic rhinitis. 5. seasonal allergies.

The correct answer is: 1,2,3 Rationale 1: Excess gastric acid production can be reduced by blocking H2 receptors. Rationale 2: Symptoms of peptic ulcer disease are decreased when H2 receptors are blocked. Rationale 3: When H2 receptors are blocked, gastric acid secretion is reduced, decreasing the symptoms of GERD. Rationale 4: The symptoms of allergic rhinitis are the result of the activation of H1 receptors. Rationale 5: The symptoms of seasonal allergies are the result of the activation of H1 receptors. Reasoning: Drugs that block H2 receptors such as ranitidine (Zantac) reduce gastric acid secretion and are used to treat peptic ulcer disease and gastroesophageal reflux disease. This histamine receptor activity is not related to allergic responses.

The nurse is reviewing the medication administration record for a client who is receiving an initial regimen for the eradication of H. pylori. The nurse anticipates the inclusion of which medications for this client? 1. Omeprazole 2. Metronidazole 3. Bismuth subsalicylate 4. Amoxicillin 5. Clarithromycin

The correct answer is: 1,4,5 Rationale 1: Omeprazole is a medication included in the initial medication regimen in the eradication of H. pylori. Rationale 2: Metronidazole is not included in the initial medication regimen in the eradication of H. pylori. Rationale 3: Bismuth subsalicylate is not included in the initial medication regimen in the eradication of H. pylori. Rationale 4: Amoxicillin is a medication included in the initial medication regimen in the eradication of H. pylori. Rationale 5: Clarithromycin is a medication included in the initial medication regimen in the eradication of H. pylori. Reasoning: Initial regimen includes: Omeprazole, clarithromycin (Biaxin), and amoxicillin (Amoxil, Others). Alternative regimens include: Omeprazole (or other PPI), clarithromycin (Biaxin), and metronidazole (Flagyl), or omeprazole (or other PPI), bismuth subsalicylate (Pepto-Bismol), metronidazole (Flagyl), and tetracycline

A client is prescribed omeprazole, bismuth subsalicylate, and metronidazole for the treatment of H. pylori. The nurse explains that combination therapy will accomplish which outcome? 1. Increase the number of ulcerations 2. Eliminate the population of H. pylori 3. Allow H. pylori to adhere to the gastric mucosa 4. Immediately relieve symptoms of gastric ulceration

The correct answer is: 2 Rationale 1: A goal of combination therapy is not to increase the number of ulcerations. Rationale 2: A goal of combination therapy is to eliminate the population of H. pylori. Rationale 3: Combination therapy will inhibit bacterial growth by disrupting their cell wall and preventing H. pylori from adhering to the gastric mucosa. Rationale 4: The goal of combination therapy is to eradicate H. pylori and heal ulcerations. Symptoms will not immediately be relieved by this therapy. Reasoning: The goal of combination therapy is to eradicate H. pylori and heal ulcerations. Symptoms will not immediately be relieved by this therapy. Combination therapy will inhibit bacterial growth by disrupting their cell wall and preventing H. pylori from adhering to the gastric mucosa.

An adult client who prescribed the anticholinergic oxybutynin (Ditropan) for urinary incontinence is admitted to the unit with acute muscle spasms after twisting her back in a fall. Which medication used for muscle spasm relaxation would cause the nurse the most concern? 1. Ibuprofen 600 mg 2. Cyclobenzaprine (Flexeril) 3. Tizanidine (Zanaflex) 4. Chlorzoxazone (Parafon Forte)

The correct answer is: 2 Rationale 1: There is no contraindication for use of ibuprofen with anticholinergics. Rationale 2: Cyclobenzaprine will enhance anticholinergic side effects and is contraindicated with anticholinergics. Rationale 3: There is no contraindication for use of tizanidine with anticholinergics. Rationale 4: There is no contraindication for use of chlorzoxazone with anticholinergics.

A client in a long-term care facility is ordered to receive ranitidine (Zantac). When should the nurse administer this medication? 1. At bedtime with water 2. After the evening meal 3. Before eating in the morning 4. One hour before meals

The correct answer is: 2 Rationale 1: Unless otherwise indicated, the drug should not be taken at bedtime. Rationale 2: The ideal time to administer ranitidine is after the evening meal, as the buffering effect of food can increase the therapeutic effect. Rationale 3: Unless otherwise indicated, the drug should not be taken on an empty stomach. Rationale 4: Unless otherwise indicated, the drug should not be taken before meals. Reasoning: The ideal time to administer ranitidine is after the evening meal, as the buffering effect of food can increase the therapeutic effect. Unless otherwise directed, it should not be taken at bedtime, on an empty stomach, or before meals.

The nurse is discharging an older adult client who was hospitalized after a muscle strain injury to his back. One of the discharge prescriptions for this client is cyclobenzaprine (Flexeril) 10 mg three times per day with food. The prescription is written for 90 tablets and there are three refills available. Which information from this situation would alert the nurse for the need to collaborate with the client's health care provider? 1. The dosage amount is too low for the type of injury this client sustained. 2. Cyclobenzaprine should be used with great caution in those over 65. 3. If taken as directed, the client would be able to take the medication for 120 days. 4. Cyclobenzaprine is not effective for back pain. 5. Cyclobenzaprine should not be taken with food.

The correct answer is: 2,3 Rationale 1: The dosage of 10 mg three times daily is standard. Rationale 2: The adverse reactions from cyclobenzaprine include confusion, hallucinations, and cardiac events, which are more common in clients over 65. Rationale 3: The manufacturer recommends that treatment not extend beyond 3 weeks or 21 days. Rationale 4: Cyclobenzaprine is not effective for muscle spasm due to spinal cord injury, but is useful in the treatment of back pain from muscle strain. Rationale 5: The drug may be taken with food or milk if gastric upset occurs.

A client who was discontinued from using an MAOI 1 week ago has injured his back and is in pain from severe muscle spasms. The client is prescribed cyclobenzaprine (Flexeril) for the muscle spasms. Which nursing action is the most important? 1. Inform the client to watch for added CNS depression. 2. Warn the client not to operate a motorized vehicle until the effects of the medication are known. 3. Hold the Flexeril and notify the health care provider. 4. Give the Flexeril as prescribed.

The correct answer is: 3 Rationale 1: Added CNS depression is not the important concern here. Rationale 2: Although the client should not operate a motorized vehicle until effects of the drug are known, this is not the most important issue. Rationale 3: A potentially fatal hypertensive crisis could occur if cyclobenzaprine is used within 14 days of an MAOI. Rationale 4: The health care provider needs to be notified that the client has not been off the MAOI for the required minimum of 14 days before the Flexeril was prescribed.

A client with a diagnosis of peptic ulcer disease is prescribed omeprazole (Prilosec) and asks the nurse where in the body this medication will work. The nurse correctly answers: 1. "On the gastric mucus layer." 2. "On the mucosa of the trachea." 3. "On the surface of parietal cells." 4. "On the H2 receptors."

The correct answer is: 3 Rationale 1: Omeprazole is a proton pump inhibitor and works on the proton pump, which is located on the surface of parietal cells. Rationale 2: Omeprazole is a proton pump inhibitor and works on the proton pump, which is located on the surface of parietal cells. Rationale 3: Omeprazole is a proton pump inhibitor and works on the proton pump, which is located on the surface of parietal cells. Rationale 4: H2-receptor antagonists work on H2 blockers. Omeprazole is a proton pump inhibitor and works on the proton pump, which is located on the surface of parietal cells. Reasoning: PPIs, such as omeprazole, reduce acid secretion in the stomach by binding irreversibly to the H, K-ATPase enzyme at the surface of the parietal cell, thereby blocking the final step in acid production. It does not work on the gastric mucosa layer or in the trachea. H2-receptor antagonists work on H2 blockers.