Clonidine hydrochloride MCQs With Answer

Clonidine hydrochloride MCQs With Answer

Clonidine hydrochloride is a centrally acting alpha-2 adrenergic agonist important in B.Pharm pharmacology and therapeutics. This introduction highlights clonidine’s mechanism of action, clinical uses (antihypertensive, ADHD, opioid withdrawal), formulations (oral immediate and extended-release, transdermal patch), pharmacokinetics, dosing considerations, adverse effects such as sedation, dry mouth and rebound hypertension, and critical drug interactions with tricyclics and CNS depressants. Emphasis is placed on monitoring, patient counselling, withdrawal risk and safe dispensing. These focused points aim to deepen understanding beyond basics, preparing students for clinical application and exam-style questions. ‘Now let’s test your knowledge with 30 MCQs on this topic.’

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

• Blockade of peripheral alpha-1 adrenergic receptors
• Central alpha-2 adrenergic receptor agonism reducing sympathetic outflow
• Beta-1 adrenergic receptor antagonism in the heart
• Inhibition of angiotensin-converting enzyme (ACE)

Correct Answer: Central alpha-2 adrenergic receptor agonism reducing sympathetic outflow

Q2. Which clinical use is clonidine commonly indicated for?

• Type 1 diabetes mellitus management
• Essential hypertension and adjunctive therapy for ADHD
• Bacterial skin infections
• Primary hyperlipidemia treatment

Correct Answer: Essential hypertension and adjunctive therapy for ADHD

Q3. Which formulation of clonidine is available for sustained systemic delivery over several days?

• Immediate-release oral tablet
• Transdermal patch
• Intravenous bolus injection
• Inhalation aerosol

Correct Answer: Transdermal patch

Q4. A major clinical risk when clonidine is stopped abruptly is:

• Hypoglycemic coma
• Rebound hypertension with sympathetic surge
• Severe hyperkalemia
• Acute pancreatitis

Correct Answer: Rebound hypertension with sympathetic surge

Q5. Which adverse effect is most commonly associated with clonidine therapy?

• Excessive salivation
• Persistent cough
• Dry mouth and sedation
• Hyperreflexia

Correct Answer: Dry mouth and sedation

Q6. Clonidine’s antihypertensive effect is primarily due to:

• Direct vasodilation of peripheral arterioles via nitric oxide
• Reduction in central sympathetic outflow leading to decreased peripheral vascular resistance
• Inhibition of renin secretion from the kidney as its only action
• Activation of beta-2 receptors causing vasodilation

Correct Answer: Reduction in central sympathetic outflow leading to decreased peripheral vascular resistance

Q7. Which drug interaction with clonidine is clinically significant and may reduce its antihypertensive efficacy?

• Combination with ACE inhibitors potentiates clonidine’s effect
• Co-administration with tricyclic antidepressants can antagonize clonidine’s antihypertensive action
• Concurrent use of metformin increases clonidine bioavailability
• Simultaneous use with vitamin C neutralizes clonidine

Correct Answer: Co-administration with tricyclic antidepressants can antagonize clonidine’s antihypertensive action

Q8. Which physiologic parameter should be monitored closely when initiating clonidine therapy?

• Serum LDL cholesterol
• Blood pressure and heart rate
• Serum calcium
• Pulmonary function test

Correct Answer: Blood pressure and heart rate

Q9. Which statement about clonidine pharmacokinetics is correct?

• Clonidine is poorly absorbed after oral administration and has negligible systemic effects
• Clonidine is well absorbed orally, undergoes hepatic metabolism and significant renal excretion
• Clonidine is exclusively excreted unchanged in feces
• Clonidine is inactivated by gastric acid and thus ineffective orally

Correct Answer: Clonidine is well absorbed orally, undergoes hepatic metabolism and significant renal excretion

Q10. Which adverse cardiovascular effect can clonidine cause, especially at higher doses?

• Tachycardia with palpitations
• Bradycardia and potential sinus node depression
• Ventricular fibrillation as the most common toxicity
• Marked hypertension immediately after single doses

Correct Answer: Bradycardia and potential sinus node depression

Q11. Clonidine is used off-label for which of the following clinical situations?

• Acute bacterial meningitis
• Opioid withdrawal symptom control and reduction of cravings
• Curing chronic hepatitis B infection
• Treatment of nephrotic syndrome

Correct Answer: Opioid withdrawal symptom control and reduction of cravings

Q12. For pediatric ADHD management, clonidine is typically used as:

• First-line monotherapy in all children
• An adjunct or alternative to stimulants, often as extended-release or patch formulations
• Only in neonates exclusively
• Given intravenously as continuous infusion

Correct Answer: An adjunct or alternative to stimulants, often as extended-release or patch formulations

Q13. Which counseling point is most important for a patient using a clonidine transdermal patch?

• Apply two patches simultaneously to increase effect
• Change the patch site as instructed, usually once weekly, and avoid abrupt removal without medical advice
• Expose the patch site to direct heat to enhance absorption
• Use the patch only while swimming to improve adherence

Correct Answer: Change the patch site as instructed, usually once weekly, and avoid abrupt removal without medical advice

Q14. Which antagonist can reverse some effects of clonidine in experimental settings?

• Propranolol
• Yohimbine, an alpha-2 adrenergic antagonist
• Nifedipine
• Losartan

Correct Answer: Yohimbine, an alpha-2 adrenergic antagonist

Q15. In clonidine overdose presenting with severe bradycardia, which immediate treatment is commonly used?

• Oral nifedipine
• Atropine for symptomatic bradycardia and supportive measures
• High-dose aspirin
• IV magnesium sulfate as first-line

Correct Answer: Atropine for symptomatic bradycardia and supportive measures

Q16. Which patient population requires dose adjustment or cautious use of clonidine due to altered elimination?

• Patients with significant renal impairment
• Young healthy adults with normal renal function
• Patients with seasonal allergies only
• Those with controlled hypothyroidism without other issues

Correct Answer: Patients with significant renal impairment

Q17. Which statement about clonidine and pregnancy/lactation is most accurate?

• Clonidine is contraindicated because it is not absorbed into maternal circulation
• Clonidine crosses the placenta and can be excreted in breast milk; use requires risk-benefit assessment
• Clonidine is the preferred antihypertensive in all pregnant patients
• Clonidine permanently sterilizes reproductive function

Correct Answer: Clonidine crosses the placenta and can be excreted in breast milk; use requires risk-benefit assessment

Q18. Which of the following is NOT a recognized clinical adverse effect of clonidine?

• Dry mouth
• Constipation and urinary retention
• Severe sedation and somnolence
• Increased risk of bacterial infections due to immunosuppression

Correct Answer: Increased risk of bacterial infections due to immunosuppression

Q19. Clonidine’s chemical form commonly used in pharmaceuticals is:

• Clonidine sulfate
• Clonidine hydrochloride
• Clonidine phosphate
• Clonidine acetate

Correct Answer: Clonidine hydrochloride

Q20. Which monitoring parameter is least relevant when a patient is stabilized on chronic clonidine therapy?

• Periodic blood pressure and heart rate checks
• Assessment for depressive symptoms or excessive sedation
• Liver function tests every week in all patients
• Evaluation for signs of rebound hypertension if doses missed

Correct Answer: Liver function tests every week in all patients

Q21. A pharmacist counseling a patient on clonidine should advise which of the following regarding alcohol or sedative use?

• Alcohol enhances clonidine’s antihypertensive effect and is encouraged
• Concomitant alcohol or CNS depressants can increase sedation and should be used cautiously
• Alcohol neutralizes clonidine and must be consumed to activate the drug
• There are no interactions between clonidine and sedatives

Correct Answer: Concomitant alcohol or CNS depressants can increase sedation and should be used cautiously

Q22. Which laboratory test best predicts clonidine efficacy in lowering blood pressure?

• Plasma renin activity is the sole predictor
• No single laboratory test; clinical blood pressure monitoring is primary
• Serum sodium correlates directly with effect
• Urine glucose indicates antihypertensive response

Correct Answer: No single laboratory test; clinical blood pressure monitoring is primary

Q23. Which is a practical dispensing precaution for clonidine tablets to reduce risk of withdrawal?

• Instruct patients to stop when blood pressure is normal and discard rest
• Taper the dose gradually under medical supervision rather than abrupt cessation
• Double the dose if one dose is missed to compensate
• Recommend self-increasing dose during stressful days

Correct Answer: Taper the dose gradually under medical supervision rather than abrupt cessation

Q24. Which statement about clonidine and beta-blocker coadministration is true?

• Combined use has no clinical consequences
• Coadministration may increase risk of bradycardia and requires monitoring
• Beta-blockers completely block clonidine’s actions making it ineffective
• They interact to cause hyperglycemia in most patients

Correct Answer: Coadministration may increase risk of bradycardia and requires monitoring

Q25. Which indication is NOT appropriate for clonidine therapy?

• Essential hypertension
• Management of ADHD symptoms in certain patients
• Treatment of acute bacterial pneumonia
• Adjunctive therapy for opioid withdrawal symptoms

Correct Answer: Treatment of acute bacterial pneumonia

Q26. Which counseling instruction helps reduce the common side effect of dry mouth from clonidine?

• Avoid all oral liquids during the day
• Use sugar-free lozenges, maintain good oral hygiene and stay hydrated
• Brush teeth only once weekly to conserve saliva
• Increase salt intake to stimulate salivation

Correct Answer: Use sugar-free lozenges, maintain good oral hygiene and stay hydrated

Q27. Extended-release oral clonidine formulations are particularly useful because they:

• Require administration multiple times per day for effect
• Provide smoother plasma concentrations and reduce peak-related adverse effects
• Are inactivated in the intestine and have no systemic absorption
• Are only used exclusively for topical dermatologic conditions

Correct Answer: Provide smoother plasma concentrations and reduce peak-related adverse effects

Q28. Which sign suggests clonidine toxicity in a patient found drowsy and hypotensive?

• Hyperactive deep tendon reflexes
• Marked miosis, bradycardia and decreased respiratory drive
• High fever and delirium due to anticholinergic effect
• Profuse urination and polydipsia

Correct Answer: Marked miosis, bradycardia and decreased respiratory drive

Q29. Which is an evidence-based clinical role of clonidine in pain management?

• Systemic clonidine is a first-line analgesic for acute fractures
• Clonidine may be used as an adjuvant for neuropathic pain and to reduce opioid requirements
• Clonidine cures osteoarthritis progression
• Topical clonidine causes systemic immune suppression

Correct Answer: Clonidine may be used as an adjuvant for neuropathic pain and to reduce opioid requirements

Q30. When counseling patients, which statement best describes safe discontinuation of clonidine?

• Stop immediately if blood pressure is low; no follow-up needed
• Reduce dose gradually under supervision to avoid rebound hypertension and sympathetic overactivity
• Substitute with another centrally acting agent without tapering
• There is no risk associated with abrupt cessation

Correct Answer: Reduce dose gradually under supervision to avoid rebound hypertension and sympathetic overactivity

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