Procainamide hydrochloride MCQs With Answer

Procainamide hydrochloride MCQs With Answer is a concise study tool for B. Pharm students to deepen understanding of procainamide, a Class IA antiarrhythmic. This resource covers mechanism of action (fast sodium channel blockade with moderate potassium effects), pharmacokinetics (N‑acetylation to NAPA, renal elimination, acetylator variability), clinical indications (ventricular arrhythmias, selected supraventricular arrhythmias), monitoring requirements (ECG, renal function, blood counts, ANA) and major adverse effects (drug‑induced lupus, agranulocytosis, hypotension, QT prolongation). Emphasis is placed on formulation as the hydrochloride salt, dosing principles, drug interactions and safety considerations relevant to pharmacy practice. The following MCQs reinforce mechanistic, clinical and safety aspects for exam and practical readiness.

Now let’s test your knowledge with 30 MCQs on this topic.

Q1. What is the primary electrophysiological mechanism of procainamide?

• Beta‑adrenergic blockade reducing heart rate
• Calcium channel blockade in the AV node
• Fast sodium channel blockade with slowed conduction and prolonged action potential
• Direct vagal stimulation causing bradycardia

Correct Answer: Fast sodium channel blockade with slowed conduction and prolonged action potential

Q2. Procainamide is classified as which Vaughan‑Williams antiarrhythmic class?

• Class II
• Class IA
• Class IC
• Class III

Correct Answer: Class IA

Q3. Which major metabolite of procainamide has Class III antiarrhythmic properties?

• Desethylprocainamide (DEPA)
• N‑acetylprocainamide (NAPA)
• Procainamide sulfate
• Procainamide glucuronide

Correct Answer: N‑acetylprocainamide (NAPA)

Q4. Which hepatic enzyme primarily catalyzes conversion of procainamide to NAPA?

• CYP3A4
• N‑acetyltransferase 2 (NAT2)
• CYP2D6
• Glutathione S‑transferase

Correct Answer: N‑acetyltransferase 2 (NAT2)

Q5. How does acetylator phenotype affect procainamide pharmacokinetics?

• Slow acetylators form NAPA faster, shortening half‑life
• Fast acetylators produce less NAPA and prolong QT substantially
• Slow acetylators have prolonged parent drug half‑life and variable NAPA accumulation
• Acetylator status has no effect on procainamide metabolism

Correct Answer: Slow acetylators have prolonged parent drug half‑life and variable NAPA accumulation

Q6. Which of the following ECG changes is typically caused by procainamide?

• Shortened PR interval and decreased QRS duration
• Prolonged PR interval, widened QRS and prolonged QT
• ST‑segment elevation in precordial leads
• Peaked T waves with shortened QT

Correct Answer: Prolonged PR interval, widened QRS and prolonged QT

Q7. A major chronic adverse effect associated with procainamide is:

• Hepatic steatosis
• Drug‑induced lupus erythematosus
• Peripheral neuropathy
• Hyperglycemia

Correct Answer: Drug‑induced lupus erythematosus

Q8. Which laboratory monitoring is important during long‑term procainamide therapy?

• Serum potassium and magnesium only
• Complete blood count, ANA, renal function and periodic ECG
• Liver biopsy annually
• Serum amylase and lipase only

Correct Answer: Complete blood count, ANA, renal function and periodic ECG

Q9. The hydrochloride salt of procainamide is used clinically primarily to:

• Decrease its potency
• Improve water solubility for IV and oral formulations
• Convert it into a prodrug activated by esterases
• Increase its lipid solubility for CNS penetration

Correct Answer: Improve water solubility for IV and oral formulations

Q10. Which of the following is a common acute adverse effect during IV administration of procainamide?

• Severe constipation
• Hypotension due to vasodilation
• Hypertension and tachycardia
• Bronchospasm

Correct Answer: Hypotension due to vasodilation

Q11. Procainamide is primarily eliminated by which route?

• Hepatobiliary excretion into feces
• Renal excretion of parent drug and NAPA
• Exhalation as unchanged drug
• Sweat and saliva secretion

Correct Answer: Renal excretion of parent drug and NAPA

Q12. Which drug interaction is most clinically relevant with procainamide?

• Concurrent use with CYP3A4 inducers decreasing procainamide levels
• Combination with other QT‑prolonging drugs increasing torsades risk
• Rifampin markedly increasing procainamide efficacy
• Proton pump inhibitors causing procainamide accumulation

Correct Answer: Combination with other QT‑prolonging drugs increasing torsades risk

Q13. In which clinical situation is procainamide commonly used acutely?

• Acute ischemic stroke to restore cerebral perfusion
• Acute management of certain ventricular tachycardias when cardioversion is not immediately available
• Treatment of acute bacterial endocarditis
• Chronic management of hypertension

Correct Answer: Acute management of certain ventricular tachycardias when cardioversion is not immediately available

Q14. NAPA accumulation is of concern because it:

• Has potent anticholinergic activity causing urinary retention
• Exerts Class III effects that can prolong repolarization and QT interval
• Is an inactive metabolite with no electrophysiologic effects
• Causes immediate hemolysis in G6PD deficiency

Correct Answer: Exerts Class III effects that can prolong repolarization and QT interval

Q15. Which patient factor increases risk of procainamide toxicity?

• Enhanced hepatic clearance due to rapid acetylation
• Renal impairment reducing excretion of drug and metabolites
• Young age with high metabolic rate
• Concomitant use of vitamin C supplements

Correct Answer: Renal impairment reducing excretion of drug and metabolites

Q16. Which adverse hematologic effect, though rare, is associated with procainamide?

• Agranulocytosis
• Polycythemia vera
• Hereditary spherocytosis
• Essential thrombocythemia

Correct Answer: Agranulocytosis

Q17. Which contraindication is most relevant when considering procainamide therapy?

• History of stable angina without conduction disease
• Complete heart block without a pacemaker
• Mild intermittent asthma
• Uncontrolled hypothyroidism

Correct Answer: Complete heart block without a pacemaker

Q18. For B. Pharm students, which monitoring parameter best helps detect procainamide‑induced lupus early?

• Serum troponin levels
• Antinuclear antibody (ANA) titers and clinical symptoms
• Fasting blood glucose
• Serum electrolytes only

Correct Answer: Antinuclear antibody (ANA) titers and clinical symptoms

Q19. Which dosing principle is key when initiating IV procainamide for arrhythmia control?

• Give a single large bolus regardless of hemodynamics
• Administer slow IV infusion with ECG and blood pressure monitoring
• Start oral tablets immediately instead of IV
• No monitoring is required during IV infusion

Correct Answer: Administer slow IV infusion with ECG and blood pressure monitoring

Q20. Which statement about procainamide’s effect on conduction velocity is correct?

• It increases conduction velocity in ventricular tissue
• It decreases conduction velocity by blocking sodium channels
• It exclusively affects AV nodal conduction without ventricular effects
• It has no effect on conduction velocity

Correct Answer: It decreases conduction velocity by blocking sodium channels

Q21. Which pharmacologic property explains why procainamide may require dose adjustment in renal failure?

• It is extensively metabolized to inactive glucuronides eliminated by bile
• Both parent drug and NAPA are renally excreted leading to accumulation
• It undergoes complete hepatic extraction unaffected by renal function
• It is stored in adipose tissue and slowly released

Correct Answer: Both parent drug and NAPA are renally excreted leading to accumulation

Q22. Which clinical sign could indicate procainamide overdose or excessive effect?

• Marked bradycardia with hypotension and widening QRS complex
• Hypertension with bounding pulses
• Increased urine output and polyuria
• Excessive salivation and lacrimation

Correct Answer: Marked bradycardia with hypotension and widening QRS complex

Q23. When counseling patients, which chronic side effect of procainamide should be emphasized for prompt reporting?

• New joint pains, fever, or rash suggesting lupus‑like syndrome
• Improved exercise tolerance
• Blurred vision as a common early sign
• Increased appetite and weight gain

Correct Answer: New joint pains, fever, or rash suggesting lupus‑like syndrome

Q24. Which antiarrhythmic effect is contributed by procainamide’s metabolite NAPA?

• Pure beta‑blockade reducing sympathetic tone
• Class III action prolonging repolarization and refractory period
• Local anesthetic effect on peripheral nerves only
• Potent calcium channel blockade at the SA node

Correct Answer: Class III action prolonging repolarization and refractory period

Q25. Which patient population requires extra caution due to higher risk of drug‑induced lupus from procainamide?

• Young children under 2 years
• Patients receiving long‑term therapy and slow acetylators
• Patients on short single‑dose therapy only
• Those with active peptic ulcer disease

Correct Answer: Patients receiving long‑term therapy and slow acetylators

Q26. Which electrolyte abnormality increases the risk of procainamide‑induced arrhythmia complications?

• Hypercalcemia
• Hypokalemia and hypomagnesemia
• Hypernatremia
• Elevated bicarbonate levels

Correct Answer: Hypokalemia and hypomagnesemia

Q27. In pharmacy practice, which counseling point about administration is correct?

• Tablet formulations are used for chronic oral therapy while IV is for acute control
• Only rectal administration is effective
• It should always be administered with dairy for absorption
• It is administered subcutaneously for rapid effect

Correct Answer: Tablet formulations are used for chronic oral therapy while IV is for acute control

Q28. Which monitoring parameter helps detect early proarrhythmic effect of procainamide?

• Periodic chest X‑ray
• Serial ECGs to assess QRS widening and QT prolongation
• Serum amylase measurements
• Pulse oximetry only

Correct Answer: Serial ECGs to assess QRS widening and QT prolongation

Q29. Which statement best describes procainamide’s role compared with lidocaine for ventricular arrhythmias?

• Procainamide is purely local anesthetic and not used for arrhythmias
• Procainamide (Class IA) is useful when broad sodium channel blockade and QT effects are acceptable; lidocaine (Class IB) preferentially affects ischemic tissue
• Lidocaine prolongs QT more than procainamide
• They are identical in mechanism and interchangeable in all cases

Correct Answer: Procainamide (Class IA) is useful when broad sodium channel blockade and QT effects are acceptable; lidocaine (Class IB) preferentially affects ischemic tissue

Q30. For exam‑oriented pharmacology, which key phrase best summarizes procainamide?

• Class IC antiarrhythmic metabolized by CYP2C9 causing hyperglycemia
• Class IA antiarrhythmic; sodium channel blocker, NAPA metabolite with Class III effect, risk of lupus and hematologic toxicity
• Pure vasodilator used for heart failure only
• Antiplatelet agent that inhibits thromboxane A2

Correct Answer: Class IA antiarrhythmic; sodium channel blocker, NAPA metabolite with Class III effect, risk of lupus and hematologic toxicity

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