Ranitidine MCQs With Answer

Ranitidine MCQs With Answer is a focused, student-friendly review tool for B.Pharm learners covering ranitidine pharmacology, mechanism of action, pharmacokinetics, clinical indications, adverse effects, drug interactions and recent regulatory concerns. This concise introduction emphasizes key concepts such as H2 receptor antagonism, acid suppression patterns, renal excretion, dosing adjustments, and differences from other H2 blockers and PPIs. Questions probe deeper points like molecular mechanism, metabolism, clinical uses (duodenal/gastric ulcers, GERD, Zollinger–Ellison), safety profile, and the NDMA recall that affected ranitidine availability. Read carefully to reinforce therapeutics, pharmacodynamics and pharmacy practice. Now let’s test your knowledge with 30 MCQs on this topic.

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

• Competitive reversible antagonism of H2 receptors on gastric parietal cells
• Irreversible inhibition of H+/K+ ATPase in parietal cells
• Stimulation of mucosal prostaglandin synthesis
• Neutralization of gastric acid by base reaction

Correct Answer: Competitive reversible antagonism of H2 receptors on gastric parietal cells

Q2. Ranitidine most effectively reduces which component of gastric acid secretion?

• Basal and nocturnal acid secretion
• Postprandial acid secretion mediated by gastrin
• Secretin-stimulated bicarbonate secretion
• Pepsinogen secretion from chief cells

Correct Answer: Basal and nocturnal acid secretion

Q3. Which intracellular signaling pathway is primarily blocked by H2 receptor antagonists like ranitidine?

• Gs protein–mediated increase in cAMP
• Gi protein–mediated decrease in cAMP
• Gq protein–mediated increase in IP3/DAG
• Tyrosine kinase receptor phosphorylation

Correct Answer: Gs protein–mediated increase in cAMP

Q4. What is the approximate oral bioavailability of ranitidine?

• About 50%
• About 10%
• About 95%
• About 75%

Correct Answer: About 50%

Q5. The elimination half-life of ranitidine in healthy adults is closest to:

• 2–3 hours
• 12–16 hours
• 30–40 minutes
• 24–36 hours

Correct Answer: 2–3 hours

Q6. What is the primary route of elimination for ranitidine?

• Renal excretion of unchanged drug
• Extensive hepatic metabolism to inactive metabolites
• Fecal excretion after biliary secretion
• Metabolism by gut flora followed by exhalation

Correct Answer: Renal excretion of unchanged drug

Q7. Which of the following adverse effects is classically less associated with ranitidine compared to cimetidine?

• Antiandrogenic effects such as gynecomastia
• Headache and dizziness
• Constipation or diarrhea
• Rare thrombocytopenia

Correct Answer: Antiandrogenic effects such as gynecomastia

Q8. How should ranitidine dosing be adjusted in patients with significant renal impairment?

• Dose reduction or increased dosing interval is required
• No adjustment is necessary because it is hepatically cleared
• Switch to twice the normal dose to maintain efficacy
• Administer only by continuous IV infusion without adjustment

Correct Answer: Dose reduction or increased dosing interval is required

Q9. Which clinical indication is ranitidine commonly used for?

• Treatment of duodenal ulcer and symptomatic GERD
• Sole therapy for H. pylori eradication
• Primary choice for peptic strictures requiring dilation
• Topical treatment for hemorrhoids

Correct Answer: Treatment of duodenal ulcer and symptomatic GERD

Q10. In Zollinger–Ellison syndrome, ranitidine is:

• Sometimes used at high doses but often less effective than PPIs
• The most effective lifelong therapy, superior to PPIs
• Contraindicated because it increases gastrin release
• Used only to eradicate H. pylori in this condition

Correct Answer: Sometimes used at high doses but often less effective than PPIs

Q11. Which drug’s oral absorption is most likely to be reduced when coadministered with ranitidine due to increased gastric pH?

• Ketoconazole
• Metformin
• Warfarin
• Amoxicillin

Correct Answer: Ketoconazole

Q12. Which statement about ranitidine’s interaction with cytochrome P450 enzymes is correct?

• Ranitidine has minimal CYP450 inhibition compared with cimetidine
• Ranitidine is a potent inhibitor of CYP3A4 and CYP2D6
• Ranitidine induces CYP1A2 leading to decreased drug levels
• Ranitidine irreversibly inactivates all hepatic CYP enzymes

Correct Answer: Ranitidine has minimal CYP450 inhibition compared with cimetidine

Q13. What regulatory action affected ranitidine products worldwide beginning in 2019–2020?

• Many ranitidine products were recalled/withdrawn due to NDMA contamination
• Ranitidine received expanded approval for OTC use in all countries
• Ranitidine was reclassified as a controlled substance
• The drug was universally recommended for pregnant women

Correct Answer: Many ranitidine products were recalled/withdrawn due to NDMA contamination

Q14. For oral doses, when is ranitidine’s peak (Tmax) concentration typically reached?

• About 1–3 hours after dosing
• Within 5 minutes after dosing
• After 24 hours of continuous dosing
• Only after IV administration

Correct Answer: About 1–3 hours after dosing

Q15. Which formulation(s) of ranitidine was commonly available before recalls?

• Oral tablets and intravenous injection
• Transdermal patch and nebulizer solution
• Topical cream and ophthalmic drops
• Only sublingual tablets

Correct Answer: Oral tablets and intravenous injection

Q16. Which laboratory abnormality has been reported rarely with ranitidine use?

• Thrombocytopenia
• Marked elevation of serum amylase in all patients
• Hypoglycemia due to insulin secretion
• Severe hypercholesterolemia universally

Correct Answer: Thrombocytopenia

Q17. Which statement about ranitidine and antacids is correct?

• Antacids can reduce ranitidine absorption if taken simultaneously; separate dosing is advisable
• Antacids potentiate ranitidine’s CYP inhibition, enhancing drug interactions
• Antacids convert ranitidine into an inactive metabolite in the stomach
• Antacids have no effect and may be coadministered at any time without issue

Correct Answer: Antacids can reduce ranitidine absorption if taken simultaneously; separate dosing is advisable

Q18. Which patient population requires special caution and usually dosing adjustment for ranitidine?

• Patients with impaired renal function
• Patients with severe hepatic enzyme induction
• Healthy young adults only
• Patients with normal renal function on intermittent therapy

Correct Answer: Patients with impaired renal function

Q19. Ranitidine’s effect on intragastric pH is primarily due to blockade of which endogenous mediator?

• Histamine acting on H2 receptors
• ACh acting on muscarinic receptors
• Gastrin acting directly on H+/K+ ATPase
• Somatostatin inhibition of acid secretion

Correct Answer: Histamine acting on H2 receptors

Q20. Which of the following is a common clinical dosing regimen for ranitidine in uncomplicated GERD (historical guideline)?

• 150 mg orally twice daily
• 10 mg orally once daily
• 500 mg orally every 6 hours
• 1000 mg orally once weekly

Correct Answer: 150 mg orally twice daily

Q21. Compared to proton pump inhibitors (PPIs), H2 blockers like ranitidine are generally:

• Faster in onset but less potent and shorter-acting for acid suppression
• Longer acting and more effective at suppressing postprandial acid
• Irreversible inhibitors of acid secretion unlike PPIs
• Preferentially used for H. pylori eradication as monotherapy

Correct Answer: Faster in onset but less potent and shorter-acting for acid suppression

Q22. Which monitoring parameter is especially important when prescribing ranitidine to elderly or renally impaired patients?

• Serum creatinine and renal function
• Serial liver biopsy
• Daily blood glucose monitoring
• Routine chest X-rays

Correct Answer: Serum creatinine and renal function

Q23. Which statement about ranitidine in pregnancy is accurate according to historical labeling and usual clinical practice?

• It was previously classified as pregnancy category B and used if clearly needed
• It is absolutely contraindicated in all trimesters
• It was universally recommended as first-line for labor induction
• It causes teratogenic effects in all animal studies

Correct Answer: It was previously classified as pregnancy category B and used if clearly needed

Q24. Ranitidine’s clinical utility may be limited in the face of which strong acid-stimulating mediator released after meals?

• Gastrin-mediated postprandial stimulation
• Prostaglandin-mediated inhibition
• Somatostatin-mediated suppression
• Secretin-mediated bicarbonate release

Correct Answer: Gastrin-mediated postprandial stimulation

Q25. Which adverse neurological symptom may be reported rarely with H2 blockers like ranitidine, especially in elderly patients?

• Confusion and delirium
• Epileptic seizures in all patients
• Permanent peripheral neuropathy in young adults
• Guaranteed improvement in cognitive function

Correct Answer: Confusion and delirium

Q26. When administered intravenously, ranitidine should be given:

• Slowly, because rapid IV bolus can cause bradycardia and hypotension
• As a rapid push to achieve immediate full effect safely
• Only via intramuscular injection to avoid cardiac effects
• Mixed with epinephrine to prevent adverse events

Correct Answer: Slowly, because rapid IV bolus can cause bradycardia and hypotension

Q27. Which statement regarding ranitidine and H. pylori is true?

• Ranitidine alone does not eradicate H. pylori; combination antibiotic regimens are required
• Ranitidine is the preferred monotherapy to cure H. pylori infection
• Ranitidine directly kills H. pylori via membrane disruption
• Ranitidine enhances H. pylori colonization and is contraindicated

Correct Answer: Ranitidine alone does not eradicate H. pylori; combination antibiotic regimens are required

Q28. Which pharmacokinetic property explains why ranitidine dosing frequency is typically twice daily rather than once daily?

• Relatively short elimination half-life necessitating multiple daily doses
• Extremely long half-life allowing once-weekly dosing
• Ineffective oral absorption so continuous infusion is required
• Formation of active metabolite with 7-day action

Correct Answer: Relatively short elimination half-life necessitating multiple daily doses

Q29. After the discovery of NDMA contamination, what is an important pharmacy practice consideration for ranitidine products?

• Verify current regulatory status and consider alternative agents like famotidine or PPIs
• Continue dispensing unchanged but warn patients to heat the tablets before use
• Recommend doubling the dose to overcome contamination effects
• Mix ranitidine with antacids to neutralize NDMA

Correct Answer: Verify current regulatory status and consider alternative agents like famotidine or PPIs

Q30. Which H2 antagonist property makes ranitidine historically preferable to cimetidine in many clinical settings?

• Less inhibition of hepatic cytochrome P450 enzymes and fewer drug interactions
• Stronger antiandrogenic effects and greater endocrine disruption
• Greater potency as a CYP450 inducer
• Exclusive topical efficacy for mucosal healing

Correct Answer: Less inhibition of hepatic cytochrome P450 enzymes and fewer drug interactions

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