Meclizine hydrochloride MCQs With Answer

Meclizine hydrochloride MCQs With Answer

Meclizine hydrochloride is a widely used H1 antihistamine and vestibular suppressant important for B.Pharm students to master. This antiemetic is indicated for motion sickness and symptomatic management of vertigo, acting via H1 receptor antagonism with mild anticholinergic properties to reduce vestibular stimulation. Key learning areas include pharmacodynamics, pharmacokinetics, usual dosing (commonly 25–50 mg orally), adverse effects (sedation, dry mouth, blurred vision), contraindications, drug interactions, and precautions in pregnancy, pediatrics, elderly and hepatic impairment. A deeper understanding helps with rational dispensing, patient counselling and overdose management. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. What is the primary mechanism of action of meclizine hydrochloride?

• Selective muscarinic receptor agonist
• H1 histamine receptor antagonist with mild anticholinergic and vestibular suppressant effects
• 5-HT3 receptor antagonist
• Prostaglandin synthesis inhibitor

Correct Answer: H1 histamine receptor antagonist with mild anticholinergic and vestibular suppressant effects

Q2. Which of the following is a primary clinical indication for meclizine?

• Major depressive disorder
• Motion sickness and vertigo
• Bacterial sinusitis
• Hypertension

Correct Answer: Motion sickness and vertigo

Q3. What is the commonly recommended adult oral dose of meclizine for prevention of motion sickness?

• 5–10 mg one hour before travel
• 25–50 mg one hour before travel
• 200 mg at bedtime
• 1–2 mg/kg every 4 hours

Correct Answer: 25–50 mg one hour before travel

Q4. Which of the following is the most common adverse effect associated with meclizine?

• Neutropenia
• Renal failure
• Sedation and drowsiness
• Severe hypertension

Correct Answer: Sedation and drowsiness

Q5. Meclizine should be used with caution in patients with which condition due to anticholinergic effects?

• Chronic otitis media
• Acute angle-closure glaucoma
• Hypothyroidism
• Iron-deficiency anemia

Correct Answer: Acute angle-closure glaucoma

Q6. Which drug interaction is most clinically relevant when meclizine is co-administered?

• Reduced efficacy of oral contraceptives
• Increased risk of bleeding with warfarin
• Additive CNS depression with alcohol and benzodiazepines
• Marked hypoglycemia with insulin

Correct Answer: Additive CNS depression with alcohol and benzodiazepines

Q7. What is the FDA pregnancy category most commonly assigned to meclizine?

• Category X
• Category D
• Category B
• Category C

Correct Answer: Category B

Q8. Which of the following adverse effects is explained by the anticholinergic activity of meclizine?

• Excessive lacrimation
• Diarrhea
• Dry mouth and blurred vision
• Bradycardia

Correct Answer: Dry mouth and blurred vision

Q9. The onset of antiemetic effect of oral meclizine is generally:

• Immediate (within 5 minutes)
• Approximately 1 hour after oral administration
• After 48 hours
• Only after chronic use for 2 weeks

Correct Answer: Approximately 1 hour after oral administration

Q10. Which statement about meclizine pharmacokinetics is correct?

• It is not absorbed orally and must be given IV
• It is primarily excreted unchanged in feces
• It undergoes hepatic metabolism with renal elimination of metabolites
• It accumulates extensively in bone tissue

Correct Answer: It undergoes hepatic metabolism with renal elimination of metabolites

Q11. Which population requires special caution or dose adjustment when prescribing meclizine?

• Young healthy adults with no comorbidities
• Patients with hepatic impairment
• Patients with mild seasonal allergies only
• Individuals with a history of migraine without vestibular symptoms

Correct Answer: Patients with hepatic impairment

Q12. Meclizine is most appropriately classified pharmacologically as a:

• H2 receptor antagonist
• H1 antihistamine with vestibular suppressant properties
• Beta-adrenergic blocker
• Selective serotonin reuptake inhibitor

Correct Answer: H1 antihistamine with vestibular suppressant properties

Q13. Which of the following is a recommended management step for severe anticholinergic toxicity from meclizine overdose?

• Administer naloxone
• Administer physostigmine under monitoring
• Give flumazenil routinely
• Immediate hemodialysis is first-line

Correct Answer: Administer physostigmine under monitoring

Q14. Which of the following brand names is associated with meclizine?

• Antivert
• Lasix
• Prozac
• Augmentin

Correct Answer: Antivert

Q15. Regarding pediatric use, meclizine is generally:

• Recommended routinely for infants under 1 year
• Contraindicated or used with caution in young children (label guidance varies; often not recommended under 12 years)
• Available only as an inhalation formulation for children
• Preferred antiemetic for neonates

Correct Answer: Contraindicated or used with caution in young children (label guidance varies; often not recommended under 12 years)

Q16. Which laboratory monitoring is routinely required for patients on meclizine?

• Frequent liver enzyme monitoring weekly
• Serum meclizine levels monthly
• No routine laboratory monitoring required for standard use
• Daily complete blood count for 2 months

Correct Answer: No routine laboratory monitoring required for standard use

Q17. In elderly patients, the main concern with meclizine therapy is:

• Enhanced renal excretion causing subtherapeutic effect
• Increased sensitivity to anticholinergic and sedative effects leading to falls and confusion
• Severe hypoglycemia risk
• Profound weight loss

Correct Answer: Increased sensitivity to anticholinergic and sedative effects leading to falls and confusion

Q18. Which statement about meclizine formulations is correct?

• Meclizine is commonly available as oral tablets (e.g., 25 mg)
• Meclizine is most commonly given as an IV infusion in outpatient clinics
• Meclizine is available only in topical cream form
• Meclizine is exclusively an inhaled medication

Correct Answer: Meclizine is commonly available as oral tablets (e.g., 25 mg)

Q19. Which symptom is least likely to be caused by therapeutic doses of meclizine?

• Dry mouth
• Constipation or urinary retention
• Excessive alertness and insomnia
• Blurred vision

Correct Answer: Excessive alertness and insomnia

Q20. Combining meclizine with which class of drugs may increase the risk of severe central nervous system depression?

• Beta-lactam antibiotics
• Benzodiazepines and opioids
• Topical antifungals
• Loop diuretics

Correct Answer: Benzodiazepines and opioids

Q21. Which clinical situation represents an appropriate therapeutic use of meclizine?

• Long-term management of chronic obstructive pulmonary disease
• Prevention of nausea and vomiting associated with motion sickness
• Acute management of bacterial meningitis
• Treatment of acute myocardial infarction

Correct Answer: Prevention of nausea and vomiting associated with motion sickness

Q22. Which monitoring or counseling point is essential when dispensing meclizine?

• Advise patients that driving or operating machinery may be impaired due to drowsiness
• Tell patients to increase alcohol intake to improve efficacy
• Instruct patients to take it with grapefruit juice daily
• Advise immediate discontinuation if mild dry mouth occurs

Correct Answer: Advise patients that driving or operating machinery may be impaired due to drowsiness

Q23. Meclizine’s duration of symptom relief after a single dose is generally reported as:

• Less than 30 minutes
• Approximately 24 hours in many patients
• One week
• Permanent after a single dose

Correct Answer: Approximately 24 hours in many patients

Q24. Which of the following is a sign of anticholinergic overdose from meclizine?

• Profuse sweating and pinpoint pupils
• Flushing, dry skin, urinary retention, hyperthermia and delirium
• Severe hypoventilation responsive to naloxone
• Marked hyperreflexia and muscle rigidity only

Correct Answer: Flushing, dry skin, urinary retention, hyperthermia and delirium

Q25. Which of the following statements about meclizine and cardiac effects is correct?

• Meclizine is well known to cause torsades de pointes in most patients
• Meclizine has minimal known risk of significant QT prolongation at recommended doses
• Meclizine is a potent vasoconstrictor used to treat hypotension
• Meclizine consistently causes bradyarrhythmias in healthy adults

Correct Answer: Meclizine has minimal known risk of significant QT prolongation at recommended doses

Q26. For a patient with severe hepatic impairment, the pharmacist should:

• Prescribe standard full doses without any caution
• Avoid meclizine or reduce dose and monitor for increased sedation and toxicity
• Double the dose due to increased clearance
• Switch to intramuscular meclizine formulation

Correct Answer: Avoid meclizine or reduce dose and monitor for increased sedation and toxicity

Q27. Which area of the nervous system is primarily targeted by meclizine to reduce vertigo?

• Spinal cord motor neurons
• Vestibular apparatus and central vestibular pathways in the brainstem
• Cerebral cortex pain centers
• Peripheral sympathetic ganglia only

Correct Answer: Vestibular apparatus and central vestibular pathways in the brainstem

Q28. Which counseling point regarding administration timing is appropriate for motion sickness prevention?

• Take meclizine immediately after reaching destination
• Take meclizine at least 1 hour before travel for optimal prophylaxis
• Take meclizine only after symptoms become severe
• Avoid taking it prior to travel to prevent drowsiness

Correct Answer: Take meclizine at least 1 hour before travel for optimal prophylaxis

Q29. Compared to older sedating antihistamines, meclizine is characterized by:

• Greater selectivity for H2 receptors
• Longer duration of action and relatively lower incidence of acute extrapyramidal reactions
• Exclusive peripheral action and no central effects
• High potential to cause serotonin syndrome

Correct Answer: Longer duration of action and relatively lower incidence of acute extrapyramidal reactions

Q30. Which statement best describes the pharmacist’s role when dispensing meclizine?

• Provide dosing, warn about sedation and interactions (alcohol/CNS depressants), and counsel on use in special populations
• Advise patients to stop all other medications when starting meclizine
• Assure patients that meclizine has no side effects and needs no counseling
• Recommend doubling the dose if the first dose is ineffective within 10 minutes

Correct Answer: Provide dosing, warn about sedation and interactions (alcohol/CNS depressants), and counsel on use in special populations

G S Sachin

I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.

Mail- Sachin@pharmacyfreak.com