Chlorcyclizine hydrochloride MCQs With Answer

Chlorcyclizine hydrochloride MCQs With Answer

by

Chlorcyclizine hydrochloride MCQs With Answer

Chlorcyclizine hydrochloride is a first‑generation H1 antihistamine commonly studied in B. Pharm pharmacology and pharmaceutics. This concise introduction covers its chemical class (diphenylmethylpiperazine), mechanism as an H1 receptor antagonist, key pharmacokinetic points such as oral absorption and hepatic metabolism, major clinical uses in allergic rhinitis and urticaria, and typical adverse effects including sedation and anticholinergic symptoms. Emphasis is placed on formulation rationale for the hydrochloride salt, analytical assay techniques used in quality control, and important drug interactions relevant to pharmacy practice. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. What is the pharmacological classification of chlorcyclizine hydrochloride?

  • Second‑generation H1 antihistamine
  • First‑generation H1 antihistamine
  • H2 receptor blocker
  • Leukotriene receptor antagonist

Correct Answer: First‑generation H1 antihistamine

Q2. Chlorcyclizine belongs to which chemical class?

  • Phenothiazine derivative
  • Diphenylmethylpiperazine derivative
  • Sulfonamide class
  • Beta‑lactam class

Correct Answer: Diphenylmethylpiperazine derivative

Q3. What is the primary mechanism of action of chlorcyclizine?

  • Inhibition of cyclooxygenase enzymes
  • H1 receptor antagonism (H1 blockade)
  • Beta‑adrenergic receptor agonism
  • Inhibition of acetylcholinesterase

Correct Answer: H1 receptor antagonism (H1 blockade)

Q4. Which of the following are common clinical indications for chlorcyclizine?

  • Bacterial sinusitis and otitis media
  • Allergic rhinitis and urticaria
  • Hypertension and angina
  • Diabetes mellitus

Correct Answer: Allergic rhinitis and urticaria

Q5. Why is the hydrochloride salt form used in formulations of chlorcyclizine?

  • To decrease oral bioavailability
  • To increase aqueous solubility and improve formulation stability
  • To convert it into a prodrug
  • To enhance lipid solubility for topical use

Correct Answer: To increase aqueous solubility and improve formulation stability

Q6. Which adverse effects are most commonly associated with chlorcyclizine?

  • Renal failure and hyperkalemia
  • Sedation and anticholinergic effects (dry mouth, blurred vision)
  • Severe hypoglycemia and tremor
  • Bone marrow suppression

Correct Answer: Sedation and anticholinergic effects (dry mouth, blurred vision)

Q7. Chlorcyclizine is considered sedating because it:

  • Does not cross the blood‑brain barrier
  • Readily crosses the blood‑brain barrier and blocks central H1 receptors
  • Acts primarily on peripheral H2 receptors
  • Stimulates central dopaminergic pathways

Correct Answer: Readily crosses the blood‑brain barrier and blocks central H1 receptors

Q8. Use of chlorcyclizine is relatively contraindicated in patients with which condition?

  • Controlled hypothyroidism
  • Narrow‑angle glaucoma
  • Corrected vitamin D deficiency
  • Mild seasonal allergies

Correct Answer: Narrow‑angle glaucoma

Q9. Chlorcyclizine can have an additive sedative effect when co‑administered with which of the following?

  • Selective serotonin reuptake inhibitors without CNS effects
  • CNS depressants such as alcohol or benzodiazepines
  • Topical emollients
  • Nonsteroidal anti‑inflammatory drugs (NSAIDs)

Correct Answer: CNS depressants such as alcohol or benzodiazepines

Q10. The primary organ responsible for the metabolism of chlorcyclizine is:

  • The kidneys (renal metabolism)
  • The liver (hepatic metabolism)
  • The lungs
  • The pancreas

Correct Answer: The liver (hepatic metabolism)

Q11. Common oral dosage forms available for chlorcyclizine hydrochloride include:

  • Tablets and syrup
  • Transdermal patches and inhalers
  • Nasal spray and rectal suppositories
  • Intrathecal injection only

Correct Answer: Tablets and syrup

Q12. Chlorcyclizine has significant activity at which other histamine receptor?

  • Strong H2 receptor agonist activity
  • Negligible H2 receptor activity; primarily H1 antagonist
  • Selective H3 receptor agonist activity
  • Potent H4 receptor antagonist

Correct Answer: Negligible H2 receptor activity; primarily H1 antagonist

Q13. After oral administration, antihistamines like chlorcyclizine typically have an onset of symptomatic relief within:

  • Several days
  • Within one hour
  • Two to three weeks
  • Onset is unpredictable and usually takes months

Correct Answer: Within one hour

Q14. Which analytical technique is commonly used in quality control assays for chlorcyclizine in pharmaceutical formulations?

  • High‑performance liquid chromatography (HPLC)
  • Gram staining
  • ELISA for proteins
  • Thermal gravimetric analysis only

Correct Answer: High‑performance liquid chromatography (HPLC)

Q15. Recommended storage conditions for chlorcyclizine hydrochloride tablets in the pharmacy are:

  • Store at high humidity and high temperature
  • Store in a cool, dry place protected from light
  • Must be frozen at all times
  • Store in direct sunlight for stability

Correct Answer: Store in a cool, dry place protected from light

Q16. Which anticholinergic symptom is commonly reported with chlorcyclizine use?

  • Excessive salivation
  • Dry mouth
  • Increased lacrimation (tearing)
  • Bradycardia with hypersalivation

Correct Answer: Dry mouth

Q17. In suspected oral overdose of chlorcyclizine in an adult presenting early, a recommended initial management step is:

  • Immediate dialysis
  • Administration of activated charcoal if within the appropriate time window
  • High‑dose aspirin
  • Exchange transfusion

Correct Answer: Administration of activated charcoal if within the appropriate time window

Q18. Special precaution for use of chlorcyclizine in pediatric patients includes:

  • No special precautions; same doses as adults
  • Use with caution in infants due to risk of paradoxical CNS depression or excitation
  • It is a first‑line treatment for neonates
  • Guaranteed to be non‑sedating in children

Correct Answer: Use with caution in infants due to risk of paradoxical CNS depression or excitation

Q19. Besides H1 antagonism, chlorcyclizine demonstrates which additional pharmacologic property?

  • Strong beta‑adrenergic agonism
  • Anticholinergic (antimuscarinic) activity
  • Direct insulinotropic activity
  • Monoamine oxidase inhibition

Correct Answer: Anticholinergic (antimuscarinic) activity

Q20. Co‑administration of chlorcyclizine with other anticholinergic drugs is likely to cause:

  • Reduced anticholinergic effects
  • Additive anticholinergic adverse effects such as dry mouth and urinary retention
  • Immediate reversal of anticholinergic effects
  • No clinically relevant interaction

Correct Answer: Additive anticholinergic adverse effects such as dry mouth and urinary retention

Q21. The most common central nervous system adverse effect that may impair patient activities is:

  • Seizures in all patients
  • Severe mania
  • Drowsiness and impaired alertness
  • Persistent euphoria

Correct Answer: Drowsiness and impaired alertness

Q22. Which clinical parameters should pharmacists counsel patients to monitor while taking chlorcyclizine?

  • Signs of hypoglycemia only
  • Symptoms of excessive sedation, urinary retention, and blurred vision
  • Daily blood pressure readings only
  • Serum electrolyte levels at home

Correct Answer: Symptoms of excessive sedation, urinary retention, and blurred vision

Q23. For acute bronchospasm in asthma, chlorcyclizine is:

  • A first‑line bronchodilator
  • Not appropriate as primary therapy for acute bronchospasm
  • An effective substitute for inhaled beta‑agonists
  • The preferred emergency medication

Correct Answer: Not appropriate as primary therapy for acute bronchospasm

Q24. The sedative effects of chlorcyclizine are primarily due to blockade of which receptors in the central nervous system?

  • Central H1 receptors
  • Peripheral H2 receptors
  • Alpha‑1 adrenergic receptors only
  • Peripheral dopamine receptors

Correct Answer: Central H1 receptors

Q25. Which of the following statements about therapeutic drug monitoring for chlorcyclizine is correct?

  • Routine plasma concentration monitoring is required for all patients
  • No routine therapeutic drug monitoring is usually necessary
  • Therapeutic range is monitored weekly by ECG
  • Serum levels must be checked before each dose

Correct Answer: No routine therapeutic drug monitoring is usually necessary

Q26. Excretion of chlorcyclizine and its metabolites primarily involves:

  • Excretion unchanged mainly via lungs
  • Hepatic metabolism with renal/biliary excretion of metabolites
  • Complete fecal excretion of unchanged drug only
  • Exclusive secretion in sweat

Correct Answer: Hepatic metabolism with renal/biliary excretion of metabolites

Q27. Which counseling point is appropriate when dispensing chlorcyclizine to patients who drive or operate machinery?

  • It will enhance alertness; safe to drive
  • Avoid driving or operating heavy machinery until you know how the drug affects you
  • Double the dose to prevent drowsiness
  • Only take the drug immediately before driving

Correct Answer: Avoid driving or operating heavy machinery until you know how the drug affects you

Q28. At the receptor level, many H1 antihistamines including chlorcyclizine are described pharmacologically as:

  • Enzyme activators
  • Inverse agonists at the H1 receptor
  • Pure receptor agonists
  • Ion channel blockers

Correct Answer: Inverse agonists at the H1 receptor

Q29. Which patient population should use chlorcyclizine with extra caution due to increased sensitivity to anticholinergic and sedative effects?

  • Young healthy adults only
  • Elderly patients
  • Patients with well‑controlled hypertension only
  • Athletes with high endurance

Correct Answer: Elderly patients

Q30. In formulation development, selecting the hydrochloride salt of chlorcyclizine primarily helps with which pharmaceutical parameter?

  • Reducing manufacturing costs to zero
  • Improving aqueous solubility for consistent oral absorption
  • Ensuring the drug becomes a gas at room temperature
  • Making the compound completely insoluble

Correct Answer: Improving aqueous solubility for consistent oral absorption

Leave a Comment