Levocetirizine MCQs With Answer

Levocetirizine MCQs With Answer

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Levocetirizine MCQs With Answer offers B. Pharm students a focused, clinical and pharmacological review of levocetirizine — the active R‑enantiomer of cetirizine. This introduction covers mechanism of action as a selective peripheral H1‑receptor antagonist, pharmacokinetics (absorption, renal elimination, half‑life), dosing, renal dose adjustment, common adverse effects, drug interactions (CNS depressants, P‑glycoprotein), therapeutic uses (allergic rhinitis, chronic urticaria) and safety in special populations. These targeted Levocetirizine MCQs with answers help strengthen understanding of pharmacology, clinical application, and patient counseling for B.Pharm coursework and pharmacy practice. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. Which best describes levocetirizine’s primary mechanism of action?

  • Selective peripheral H1‑receptor antagonist (inverse agonist)
  • Central H2 receptor blocker
  • Mast cell stabilizer preventing degranulation
  • Leukotriene receptor antagonist

Correct Answer: Selective peripheral H1‑receptor antagonist (inverse agonist)

Q2. Levocetirizine is structurally best described as:

  • The S‑enantiomer of loratadine
  • A racemic mixture of cetirizine enantiomers
  • The R‑enantiomer (active enantiomer) of cetirizine
  • An epimer of fexofenadine

Correct Answer: The R‑enantiomer (active enantiomer) of cetirizine

Q3. What is the approximate elimination half‑life of levocetirizine in healthy adults?

  • Approximately 1–2 hours
  • Approximately 7–10 hours
  • Approximately 24–36 hours
  • Over 72 hours

Correct Answer: Approximately 7–10 hours

Q4. The major route of elimination for levocetirizine is:

  • Hepatic metabolism followed by biliary excretion
  • Renal excretion primarily as unchanged drug
  • Expired air as volatile metabolites
  • Sequestration in adipose tissue with slow release

Correct Answer: Renal excretion primarily as unchanged drug

Q5. Typical onset of symptomatic relief after oral levocetirizine administration is:

  • Within 15 minutes
  • Within 1 hour
  • After 6–8 hours
  • After 48 hours

Correct Answer: Within 1 hour

Q6. Compared with first‑generation antihistamines, levocetirizine is:

  • More sedating and has strong anticholinergic effects
  • Less sedating with minimal anticholinergic activity
  • Equally sedating but more antimuscarinic
  • Primarily a muscarinic antagonist rather than an H1 blocker

Correct Answer: Less sedating with minimal anticholinergic activity

Q7. Which therapeutic indications are main approved uses for levocetirizine?

  • Asthma maintenance therapy and COPD exacerbations
  • Allergic rhinitis and chronic idiopathic urticaria
  • Acute bacterial sinusitis and otitis media
  • Gastroesophageal reflux disease

Correct Answer: Allergic rhinitis and chronic idiopathic urticaria

Q8. The standard adult oral dose of levocetirizine for allergic symptoms is:

  • 0.5 mg once daily
  • 5 mg once daily
  • 20 mg twice daily
  • 50 mg once weekly

Correct Answer: 5 mg once daily

Q9. What is the recommended approach for levocetirizine in patients with renal impairment?

  • No adjustment needed regardless of renal function
  • Increase dose due to decreased clearance
  • Reduce dose or extend dosing interval based on creatinine clearance
  • Switch to intravenous formulation

Correct Answer: Reduce dose or extend dosing interval based on creatinine clearance

Q10. Levocetirizine’s penetration into the central nervous system is limited primarily because it is a substrate for:

  • Monoamine oxidase A
  • P-glycoprotein (P‑gp) efflux transporter
  • Organic anion transporting polypeptide (OATP)
  • Renal organic cation transporter (OCT)

Correct Answer: P-glycoprotein (P‑gp) efflux transporter

Q11. Which statement best describes levocetirizine metabolism?

  • Extensively metabolized by CYP3A4 to active metabolites
  • Minimal hepatic metabolism; largely excreted unchanged
  • Converted to active glucuronide conjugates exclusively
  • Metabolized into a cardiotoxic metabolite requiring ECG monitoring

Correct Answer: Minimal hepatic metabolism; largely excreted unchanged

Q12. Regarding pregnancy safety, levocetirizine is generally classified as:

  • Contraindicated in all trimesters
  • Pregnancy category X
  • Pregnancy category B (use only if clearly needed)
  • Known teratogen in humans

Correct Answer: Pregnancy category B (use only if clearly needed)

Q13. For pediatric patients aged 6 years and older, the usual levocetirizine dose is:

  • 0.5 mg once daily
  • 2.5 mg twice daily
  • 5 mg once daily
  • 10 mg twice daily

Correct Answer: 5 mg once daily

Q14. Which interaction is clinically important with levocetirizine?

  • Potentiation of CNS depression with alcohol and sedatives
  • Severe hepatotoxicity when combined with acetaminophen
  • Marked induction of CYP2D6 leading to reduced efficacy
  • Precipitation of serotonin syndrome with SSRIs

Correct Answer: Potentiation of CNS depression with alcohol and sedatives

Q15. Levocetirizine’s anticholinergic side effects are typically:

  • Pronounced, causing urinary retention and severe dry mouth
  • Minimal compared with first‑generation antihistamines
  • So severe that it is rarely prescribed
  • Only observed when administered intravenously

Correct Answer: Minimal compared with first‑generation antihistamines

Q16. The extent of levocetirizine binding to plasma proteins is approximately:

  • Negligible (<10%)
  • Moderate (~50%)
  • High (~90%)
  • Irreversible binding to albumin

Correct Answer: High (~90%)

Q17. Which transport protein affects levocetirizine disposition and limits CNS exposure?

  • Glucose transporter GLUT1
  • P-glycoprotein (P‑gp)
  • Na+/K+ ATPase
  • Multidrug resistance‑associated protein 2 (MRP2)

Correct Answer: P-glycoprotein (P‑gp)

Q18. Compared with racemic cetirizine, levocetirizine is:

  • Less potent and more sedating
  • More potent and generally has fewer adverse effects
  • Chemically unrelated and used for different indications
  • A prodrug requiring activation by CYP enzymes

Correct Answer: More potent and generally has fewer adverse effects

Q19. The most commonly reported adverse effects of levocetirizine include:

  • Severe gastrointestinal bleeding and pancreatitis
  • Somnolence and headache
  • Excessive sweating and polyuria
  • Hypertension and tachycardia

Correct Answer: Somnolence and headache

Q20. At therapeutic doses, levocetirizine’s effect on cardiac QT interval is generally:

  • Associated with marked QT prolongation and arrhythmia risk
  • No significant QT prolongation at recommended doses
  • Causes immediate torsades de pointes in most patients
  • Requires routine ECG monitoring in all patients

Correct Answer: No significant QT prolongation at recommended doses

Q21. Oral bioavailability of levocetirizine is best described as:

  • Very poor (<20%)
  • Moderate (40–60%)
  • High (>90%)
  • Zero due to first‑pass inactivation

Correct Answer: High (>90%)

Q22. Levocetirizine is a substrate of which of the following transporters, influencing drug interactions?

  • Cytochrome P450 2E1
  • P-glycoprotein (P‑gp)
  • Monoamine transporters
  • Catechol‑O‑methyltransferase

Correct Answer: P-glycoprotein (P‑gp)

Q23. Regarding nasal congestion in allergic rhinitis, levocetirizine is:

  • Highly effective as a decongestant
  • Less effective for congestion than topical decongestants
  • The preferred single agent for immediate decongestion
  • Contraindicated when congestion is present

Correct Answer: Less effective for congestion than topical decongestants

Q24. In which clinical scenario is levocetirizine use most concerning without dose modification?

  • Mild hepatic steatosis with normal renal function
  • Severe renal impairment with low creatinine clearance
  • Short‑term use for acute travel nausea
  • Topical dermatologic application

Correct Answer: Severe renal impairment with low creatinine clearance

Q25. Concerning cytochrome P450 interactions, levocetirizine is best characterized as:

  • A major CYP3A4 inhibitor causing many drug interactions
  • Extensively metabolized by CYP2D6 into active metabolites
  • Minimal CYP‑mediated metabolism with low potential for CYP interactions
  • A potent inducer of multiple CYP enzymes

Correct Answer: Minimal CYP‑mediated metabolism with low potential for CYP interactions

Q26. Levocetirizine use in infants younger than 6 months is generally:

  • Routinely recommended as first‑line therapy
  • Not recommended without specialist guidance
  • Indicated at 5 mg twice daily
  • Required for routine vaccination schedules

Correct Answer: Not recommended without specialist guidance

Q27. The typical dosing frequency for levocetirizine and rationale is:

  • Twice daily due to short half‑life
  • Once daily because of prolonged H1 blockade and convenient half‑life
  • Every 12 hours by IV infusion only
  • Once weekly due to depot formulation

Correct Answer: Once daily because of prolonged H1 blockade and convenient half‑life

Q28. Which common brand name corresponds to levocetirizine?

  • Zyrtec
  • Xyzal
  • Claritin
  • Benadryl

Correct Answer: Xyzal

Q29. A key pharmacological advantage of levocetirizine over racemic cetirizine is:

  • It is pro‑arrhythmic at low doses
  • It is the active enantiomer with higher receptor affinity and fewer side effects
  • It requires hepatic activation to work
  • It is an H2 receptor antagonist rather than H1

Correct Answer: It is the active enantiomer with higher receptor affinity and fewer side effects

Q30. For safe long‑term use of levocetirizine in elderly patients, pharmacists should primarily monitor:

  • Liver function tests weekly
  • Serum creatinine and renal function for dose adjustment
  • Blood glucose closely due to hypoglycemia risk
  • Coagulation profile because of bleeding risk

Correct Answer: Serum creatinine and renal function for dose adjustment

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