Lansoprazole MCQs With Answer

Lansoprazole MCQs With Answer

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Lansoprazole MCQs With Answer for B. Pharm students. This concise, focused introduction covers lansoprazole — a proton pump inhibitor (PPI) — emphasizing mechanism of action, prodrug activation, and irreversible inhibition of the H+/K+ ATPase. Content includes pharmacokinetics (absorption, enteric-coated formulations, bioavailability, CYP2C19/CYP3A4 metabolism), dosing and clinical uses (GERD, peptic ulcer, Zollinger–Ellison), adverse effects (hypomagnesemia, B12 deficiency, bone risk), drug interactions (clopidogrel, azoles), formulation and stability, and special population considerations. Questions are designed to deepen pharmaceutics, pharmacology and therapeutics understanding for safe dispensing and counseling. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. What is the primary mechanism of action of lansoprazole?

  • Reversible antagonism of H2 receptors on parietal cells
  • Irreversible inhibition of the gastric H+/K+ ATPase (proton pump)
  • Neutralization of gastric acid by direct chemical reaction
  • Blocking acetylcholine receptors on parietal cells

Correct Answer: Irreversible inhibition of the gastric H+/K+ ATPase (proton pump)

Q2. Lansoprazole is administered as a prodrug because:

  • It requires hepatic conjugation to become active
  • It must be activated in acidic canaliculi of parietal cells to form the active sulfenamide
  • It is activated by plasma esterases
  • It is converted to active form by intestinal bacteria

Correct Answer: It must be activated in acidic canaliculi of parietal cells to form the active sulfenamide

Q3. Which cytochrome P450 isoenzyme primarily metabolizes lansoprazole?

  • CYP1A2
  • CYP2D6
  • CYP2C19
  • CYP2E1

Correct Answer: CYP2C19

Q4. Why are lansoprazole formulations enteric-coated?

  • To increase bitterness for compliance
  • To protect the drug from degradation by gastric acid and allow absorption in the intestine
  • To make the tablet dissolve faster in the stomach
  • To prevent hepatic first-pass metabolism

Correct Answer: To protect the drug from degradation by gastric acid and allow absorption in the intestine

Q5. Which clinical condition is NOT a typical indication for lansoprazole?

  • Gastroesophageal reflux disease (GERD)
  • Peptic ulcer disease
  • Zollinger–Ellison syndrome
  • Acute bacterial gastroenteritis

Correct Answer: Acute bacterial gastroenteritis

Q6. Typical starting oral dose of lansoprazole for uncomplicated GERD in adults is:

  • 5 mg once daily
  • 15–30 mg once daily
  • 100 mg once daily
  • 1 mg twice daily

Correct Answer: 15–30 mg once daily

Q7. The duration of acid suppression by lansoprazole is longer than its plasma half-life because:

  • It accumulates in plasma over days
  • It irreversibly inactivates proton pumps, requiring new pump synthesis for recovery
  • It has active metabolites with long half-lives
  • It binds to gastric mucin for prolonged release

Correct Answer: It irreversibly inactivates proton pumps, requiring new pump synthesis for recovery

Q8. A known long-term adverse effect associated with chronic PPI use including lansoprazole is:

  • Hyperkalemia
  • Hypomagnesemia
  • Hemolytic anemia
  • Pancreatitis

Correct Answer: Hypomagnesemia

Q9. Lansoprazole can reduce the activation of clopidogrel due to:

  • Induction of CYP3A4 leading to clopidogrel inactivation
  • Inhibition of CYP2C19 which is needed to convert clopidogrel to its active metabolite
  • Binding to clopidogrel in the gut, preventing absorption
  • Enhancing renal clearance of clopidogrel

Correct Answer: Inhibition of CYP2C19 which is needed to convert clopidogrel to its active metabolite

Q10. Which counseling point is appropriate when dispensing enteric-coated lansoprazole granules?

  • Crush the capsule and mix with antacid before administration
  • Open capsules and sprinkle granules on soft food or mix with water, do not crush the granules
  • Take with a large fatty meal to increase absorption
  • Chew the granules thoroughly before swallowing

Correct Answer: Open capsules and sprinkle granules on soft food or mix with water, do not crush the granules

Q11. Which laboratory parameter should be monitored during long-term lansoprazole therapy?

  • Serum calcium only
  • Serum magnesium and vitamin B12 if clinically indicated
  • Fasting glucose monthly
  • Liver enzymes weekly

Correct Answer: Serum magnesium and vitamin B12 if clinically indicated

Q12. Lansoprazole’s onset of maximal acid suppression typically occurs:

  • Within 5 minutes of dosing
  • After several days of daily dosing due to accumulation of pump inhibition
  • Only after one month of therapy
  • Immediately after the first dose with peak effect in 10 minutes

Correct Answer: After several days of daily dosing due to accumulation of pump inhibition

Q13. Which statement about lansoprazole and food is most accurate?

  • Food has no effect; it can be taken any time
  • Food increases its bioavailability greatly; always take with a large meal
  • Administration is usually recommended before meals to optimize effect
  • It must be taken with milk to prevent stomach upset

Correct Answer: Administration is usually recommended before meals to optimize effect

Q14. Which of the following is a formulation advantage of orally disintegrating or capsule-sprinkle lansoprazole?

  • They allow immediate gastric absorption without enteric protection
  • They permit administration to patients who cannot swallow intact capsules
  • They remove the need to protect the drug from acid degradation
  • They are designed for intravenous use

Correct Answer: They permit administration to patients who cannot swallow intact capsules

Q15. In H. pylori eradication regimens, lansoprazole is combined with antibiotics because:

  • It directly kills H. pylori organisms
  • Acid suppression increases antibiotic stability and efficacy in the stomach
  • It neutralizes antibiotics making them safer
  • It enhances gastric motility to deliver antibiotics faster

Correct Answer: Acid suppression increases antibiotic stability and efficacy in the stomach

Q16. Which adverse effect is associated with PPI-induced hypochlorhydria relevant to nutrient absorption?

  • Increased iron absorption
  • Reduced vitamin B12 absorption due to decreased gastric acid
  • Hypervitaminosis D
  • Increased folate absorption

Correct Answer: Reduced vitamin B12 absorption due to decreased gastric acid

Q17. Which patient factor can significantly alter lansoprazole metabolism and exposure?

  • Genetic polymorphism of CYP2C19 resulting in poor metabolizer phenotype
  • Blood type A versus B
  • Presence of allergy to penicillin
  • Recent influenza vaccination

Correct Answer: Genetic polymorphism of CYP2C19 resulting in poor metabolizer phenotype

Q18. Which statement regarding lansoprazole stability and storage is correct?

  • Enteric-coated granules can be stored in hot, humid conditions without effect
  • Tablets and capsules should be kept in original container away from moisture and heat
  • It must be refrigerated at 2–8°C
  • Once opened, capsules are stable for years at room temperature

Correct Answer: Tablets and capsules should be kept in original container away from moisture and heat

Q19. Which lab interaction is expected when a patient takes lansoprazole long term?

  • Marked increase in serum potassium
  • Reduced absorption of drugs requiring acidic environment, like ketoconazole
  • Increased clearance of aminoglycosides
  • False increase in serum troponin levels

Correct Answer: Reduced absorption of drugs requiring acidic environment, like ketoconazole

Q20. The most appropriate action when stopping long-term lansoprazole to minimize rebound acid hypersecretion is to:

  • Stop abruptly without further measures
  • Taper the dose or switch to H2 blocker temporarily
  • Double the dose for a week then stop
  • Replace with high-dose antacid indefinitely

Correct Answer: Taper the dose or switch to H2 blocker temporarily

Q21. Which of the following best describes lansoprazole’s effect on gastric pH?

  • Causes immediate, short-lived acid neutralization only
  • Produces sustained increase in gastric pH with daily dosing
  • Has no significant effect on gastric acidity
  • Only affects duodenal pH without altering gastric pH

Correct Answer: Produces sustained increase in gastric pH with daily dosing

Q22. Which statement about pediatric use of lansoprazole is accurate?

  • Lansoprazole is never used in children
  • Dosing must be adjusted by weight and formulations suitable for children are available
  • Children always receive adult fixed doses
  • It is contraindicated in all infants under 12 months

Correct Answer: Dosing must be adjusted by weight and formulations suitable for children are available

Q23. Which adverse skeletal effect has been associated with long-term PPI therapy including lansoprazole?

  • Increased bone mineral density
  • Increased risk of osteoporotic fractures with long-term high-dose use
  • Complete protection against fractures
  • Immediate induction of osteosarcoma

Correct Answer: Increased risk of osteoporotic fractures with long-term high-dose use

Q24. For patients with severe hepatic impairment, the dosing of lansoprazole should be:

  • Increased due to rapid clearance
  • Adjusted or used cautiously because hepatic metabolism is affected
  • Unchanged since hepatic function does not affect lansoprazole
  • Stopped and replaced with a cholinomimetic

Correct Answer: Adjusted or used cautiously because hepatic metabolism is affected

Q25. A pharmacist counseling a patient starting lansoprazole should advise that symptom relief may take:

  • Minutes after the first dose
  • Several days of regular dosing for maximal effect
  • A year of continuous therapy
  • No time—symptoms will worsen initially

Correct Answer: Several days of regular dosing for maximal effect

Q26. Which pharmacokinetic property is typical for lansoprazole?

  • Very long plasma half-life of several days
  • Short plasma half-life but prolonged pharmacodynamic effect on acid secretion
  • No hepatic metabolism; excreted unchanged in urine
  • Extensive renal excretion of active drug

Correct Answer: Short plasma half-life but prolonged pharmacodynamic effect on acid secretion

Q27. Which combination is commonly used as part of triple therapy to eradicate H. pylori along with lansoprazole?

  • Amoxicillin and clarithromycin
  • Metformin and insulin
  • Warfarin and aspirin
  • Rifampicin and isoniazid

Correct Answer: Amoxicillin and clarithromycin

Q28. Which precaution is appropriate when co-prescribing lansoprazole with atazanavir or nelfinavir (HIV protease inhibitors)?

  • No precautions; they have synergistic effects
  • Use caution because increased gastric pH can reduce absorption and efficacy of these drugs
  • Double the dose of protease inhibitor automatically
  • They cause immediate severe hypoglycemia together

Correct Answer: Use caution because increased gastric pH can reduce absorption and efficacy of these drugs

Q29. Which statement about bioequivalence and generic lansoprazole products is important for pharmacists?

  • All generics are identical in excipient and release characteristics to brand without review
  • Generic and brand products claiming bioequivalence should provide similar plasma exposure, but formulation differences (enteric coating) can affect onset and handling
  • Generic lansoprazole is always less effective
  • Bioequivalence is irrelevant for drugs with enteric coatings

Correct Answer: Generic and brand products claiming bioequivalence should provide similar plasma exposure, but formulation differences (enteric coating) can affect onset and handling

Q30. Which monitoring or precaution is most relevant when a patient on lansoprazole presents with recurrent diarrhea?

  • Assume viral infection and ignore PPI use
  • Evaluate for possible Clostridioides difficile infection associated with PPI therapy
  • Immediately double the lansoprazole dose
  • Switch to high-dose NSAID therapy

Correct Answer: Evaluate for possible Clostridioides difficile infection associated with PPI therapy

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