Pentazocine MCQs With Answer

Pentazocine MCQs With Answer provides B. Pharm students a concise, exam-focused review of pentazocine — a benzomorphan opioid analgesic. This introduction covers key topics: mechanism of action (kappa agonism and partial mu antagonism), clinical uses, pharmacokinetics, adverse effects such as dysphoria and respiratory effects, dependence liability, drug interactions and formulations. These targeted MCQs reinforce understanding of pharmacology, therapeutic considerations, dosing principles and safety issues relevant to pharmacy practice. Ideal for revision and assessment, the questions progress from basic concepts to clinical scenarios to deepen learning and critical thinking. Now let’s test your knowledge with 50 MCQs on this topic.

Q1. Which primary opioid receptor subtype mediates the analgesic effect of pentazocine?

• Mu (μ) receptor
• Kappa (κ) receptor
• Delta (δ) receptor
• Nociceptin receptor

Correct Answer: Kappa (κ) receptor

Q2. Pentazocine is pharmacologically classified as which type of opioid?

• Pure mu agonist
• Mixed agonist-antagonist
• Pure antagonist
• Partial delta agonist

Correct Answer: Mixed agonist-antagonist

Q3. Which statement best describes pentazocine’s action at the mu (μ) receptor?

• Full agonist producing strong euphoria
• Pure antagonist with no analgesia
• Partial agonist or weak antagonist reducing classic mu effects
• Irreversible mu receptor blocker

Correct Answer: Partial agonist or weak antagonist reducing classic mu effects

Q4. Pentazocine belongs to which chemical class of opioids?

• Phenanthrenes
• Benzomorphans
• Synthetic diphenylheptanes
• Propionamides

Correct Answer: Benzomorphans

Q5. Compared to morphine, pentazocine’s analgesic potency is generally:

• Much higher
• Approximately the same
• Lower or less potent
• Completely ineffective as an analgesic

Correct Answer: Lower or less potent

Q6. Which adverse effect is particularly associated with pentazocine due to kappa receptor activation?

• Euphoria and intense sedation
• Dysphoria and psychotomimetic effects
• Profound bradycardia
• Significant anticholinergic effects

Correct Answer: Dysphoria and psychotomimetic effects

Q7. Pentazocine can precipitate withdrawal in which patient group?

• Opioid-naïve patients only
• Patients dependent on pure mu agonists
• Patients on benzodiazepines exclusively
• Patients taking NSAIDs regularly

Correct Answer: Patients dependent on pure mu agonists

Q8. Which formulation combination was used to deter parenteral abuse of pentazocine?

• Pentazocine + paracetamol
• Pentazocine + naloxone
• Pentazocine + promethazine
• Pentazocine + diazepam

Correct Answer: Pentazocine + naloxone

Q9. The ceiling effect observed with pentazocine refers mainly to which adverse effect?

• Analgesia
• Respiratory depression
• Nausea
• Constipation

Correct Answer: Respiratory depression

Q10. Which clinical use is most appropriate for pentazocine?

• Chronic neuropathic pain as first-line therapy
• Severe acute pain where full mu agonists are contraindicated
• Primary treatment for opioid dependence maintenance
• Antidepressant therapy

Correct Answer: Severe acute pain where full mu agonists are contraindicated

Q11. The major route of elimination for pentazocine and its metabolites is:

• Hepatic excretion into bile unchanged
• Renal excretion
• Pulmonary exhalation
• Fecal elimination as unchanged drug

Correct Answer: Renal excretion

Q12. Which pharmacokinetic property of pentazocine affects its oral use?

• High oral bioavailability due to no first-pass effect
• Significant first-pass metabolism reducing bioavailability
• Complete absorption with no metabolism
• Exclusive absorption via sublingual route

Correct Answer: Significant first-pass metabolism reducing bioavailability

Q13. Which of the following is a common opioid adverse effect that also occurs with pentazocine?

• Hypertension and hyperthermia only
• Constipation and nausea
• Marked hypoglycemia
• Severe anticholinergic delirium

Correct Answer: Constipation and nausea

Q14. In an opioid-tolerant patient, administration of pentazocine may result in:

• Enhanced analgesia without withdrawal risk
• Precipitated withdrawal symptoms
• No pharmacologic effect at all
• Immediate allergic reaction in all patients

Correct Answer: Precipitated withdrawal symptoms

Q15. Which monitoring parameter is most critical after IV pentazocine administration?

• Serum potassium
• Respiratory rate and oxygenation
• Liver biopsy results
• Visual acuity

Correct Answer: Respiratory rate and oxygenation

Q16. Pentazocine’s psychotomimetic adverse effects are primarily due to:

• Blockade of NMDA receptors
• Kappa receptor activation in the CNS
• Serotonin reuptake inhibition
• Peripheral alpha-1 receptor stimulation

Correct Answer: Kappa receptor activation in the CNS

Q17. Which statement about pentazocine and cardiovascular effects is correct?

• It consistently causes severe bradycardia in therapeutic doses
• It may increase blood pressure and heart rate in some patients
• It has potent antiarrhythmic properties
• It is contraindicated in all patients with hypertension

Correct Answer: It may increase blood pressure and heart rate in some patients

Q18. Which patient population is at higher risk of adverse effects from pentazocine?

• Patients with chronic liver disease
• Young healthy adults
• Patients with well-controlled asthma
• Patients taking topical NSAIDs

Correct Answer: Patients with chronic liver disease

Q19. Which drug interaction is clinically significant with pentazocine?

• Concurrent use with benzodiazepines increasing sedation and respiratory depression
• Pseudoephedrine reducing pentazocine levels
• Concomitant vitamin C increasing analgesia
• Topical cortisone inactivating pentazocine

Correct Answer: Concurrent use with benzodiazepines increasing sedation and respiratory depression

Q20. In overdose of pentazocine, which sign may be less pronounced compared with pure mu agonist overdose?

• Miosis (pinpoint pupils)
• Respiratory depression due to ceiling effect
• Bradycardia and hypotension
• Loss of consciousness

Correct Answer: Respiratory depression due to ceiling effect

Q21. Which antidote can reverse opioid effects including those of pentazocine in severe overdose?

• Flumazenil
• Naloxone
• Physostigmine
• Atropine

Correct Answer: Naloxone

Q22. Which clinical scenario is a relative contraindication to giving pentazocine?

• Acute myocardial infarction with ongoing opioid dependence
• Postoperative moderate pain in opioid-naïve patient
• Short-term use for dental pain in nondependent patient
• As an adjunct in emergency care where mu agonists are unavailable

Correct Answer: Acute myocardial infarction with ongoing opioid dependence

Q23. Which description best fits pentazocine’s duration of analgesic action after a single dose?

• Ultra-short acting (minutes)
• Short to intermediate duration (few hours)
• Very long-acting (days)
• Irreversible analgesic effect

Correct Answer: Short to intermediate duration (few hours)

Q24. Which laboratory test is most useful to assess accumulation risk of pentazocine in renal impairment?

• Serum creatinine and creatinine clearance
• Serum magnesium
• Fasting blood glucose
• Platelet count

Correct Answer: Serum creatinine and creatinine clearance

Q25. Pentazocine may cause which effect when administered to a patient on monoamine oxidase (MAO) inhibitors?

• No interaction expected
• Potential for exaggerated CNS stimulation or adverse reactions
• Guaranteed protection from withdrawal
• Complete inactivation of pentazocine

Correct Answer: Potential for exaggerated CNS stimulation or adverse reactions

Q26. Which formulation routes are commonly used for pentazocine administration?

• IV, IM, SC and oral routes
• Transdermal patch only
• Inhalational aerosol only
• Topical gel exclusively

Correct Answer: IV, IM, SC and oral routes

Q27. Which is an appropriate counseling point for patients prescribed oral pentazocine?

• Expect immediate and permanent relief with a single dose
• Avoid driving or operating machinery until you know how it affects you
• It is safe to drink alcohol while taking it
• No risk of constipation

Correct Answer: Avoid driving or operating machinery until you know how it affects you

Q28. The risk of physical dependence with pentazocine compared with pure mu agonists is generally:

• Higher
• Lower but still present
• Nonexistent
• Complete and immediate

Correct Answer: Lower but still present

Q29. Which of the following is a distinguishing pharmacodynamic property of mixed agonist-antagonists like pentazocine?

• They enhance mu receptor-mediated euphoric effects
• They can antagonize effects of full mu agonists
• They irreversibly bind to opioid receptors
• They exclusively act on peripheral opioid receptors

Correct Answer: They can antagonize effects of full mu agonists

Q30. In a toxicity case, which sign would most strongly suggest opioid involvement including pentazocine?

• Mydriasis (dilated pupils)
• Miosis (pinpoint pupils)
• Hyperreflexia only
• Rash and urticaria exclusively

Correct Answer: Miosis (pinpoint pupils)

Q31. Which statement about pentazocine metabolism is most accurate?

• It is excreted unchanged mainly in bile
• It undergoes hepatic metabolism before renal elimination
• It is metabolized exclusively by renal tubular secretion
• It is activated by prodrug conversion in the bloodstream

Correct Answer: It undergoes hepatic metabolism before renal elimination

Q32. When used in combination formulations (e.g., with naloxone), the primary goal is to:

• Increase analgesic potency
• Deter parenteral abuse
• Enhance gastrointestinal absorption
• Treat hypertension

Correct Answer: Deter parenteral abuse

Q33. Pentazocine-induced psychotomimetic effects may limit its use in patients with:

• History of psychosis or schizophrenia
• Mild seasonal allergies
• Controlled hypothyroidism
• Stable angina under treatment

Correct Answer: History of psychosis or schizophrenia

Q34. Which sign suggests that pentazocine has been administered intramuscularly rather than intravenously?

• Immediate peak plasma levels within seconds
• Slower onset of analgesia and localized injection site pain
• Painless administration always
• No systemic absorption occurs

Correct Answer: Slower onset of analgesia and localized injection site pain

Q35. For a B. Pharm student, knowing pentazocine’s legal scheduling is important because it:

• Has no regulations and can be bought OTC worldwide
• Is subject to controlled substance regulations and prescription requirements
• Is banned in all countries for medical use
• Is classified as a dietary supplement

Correct Answer: Is subject to controlled substance regulations and prescription requirements

Q36. Which of the following adverse effects is less likely with pentazocine compared with a full mu agonist?

• Dysphoria
• Severe euphoria and intense sedation
• Constipation
• Nausea

Correct Answer: Severe euphoria and intense sedation

Q37. Pentazocine’s analgesic effect is primarily mediated centrally at which location?

• Peripheral nociceptors only
• Spinal cord and supraspinal sites
• Neuromuscular junctions
• Gastrointestinal mucosa

Correct Answer: Spinal cord and supraspinal sites

Q38. In the context of pain management, pentazocine is most appropriately reserved for:

• Long-term cancer pain management as first-line
• Short-term management of moderate to severe pain where alternatives are unsuitable
• Chronic neuropathic pain as monotherapy
• Routine use in opioid substitution therapy

Correct Answer: Short-term management of moderate to severe pain where alternatives are unsuitable

Q39. Which monitoring consideration is particularly important in elderly patients receiving pentazocine?

• Increased risk of hypoglycemia
• Increased sensitivity to CNS effects and fall risk
• No need for dose adjustment ever
• Guaranteed tolerance to psychotomimetic effects

Correct Answer: Increased sensitivity to CNS effects and fall risk

Q40. Which is true about combining pentazocine with other opioid analgesics?

• It always produces synergistic analgesia without risk
• It may antagonize analgesia from pure mu agonists
• It enhances mu agonist euphoric effects
• It is recommended for opioid rotation to increase tolerance

Correct Answer: It may antagonize analgesia from pure mu agonists

Q41. Which clinical sign would indicate pentazocine-induced histamine release?

• Widespread bruising
• Flushing, pruritus and urticaria
• Severe hypothermia
• Isolated loss of taste

Correct Answer: Flushing, pruritus and urticaria

Q42. What is a pharmacological reason pentazocine may be less preferred in obstetric analgesia?

• It has no placental transfer
• Potential neonatal respiratory depression and unpredictable effects
• Guaranteed prevention of postpartum hemorrhage
• It accelerates labor consistently

Correct Answer: Potential neonatal respiratory depression and unpredictable effects

Q43. Which biochemical process primarily contributes to pentazocine elimination?

• Phase I hepatic metabolism followed by renal excretion
• Complete phase II conjugation only in plasma
• Direct unchanged biliary elimination only
• Enzymatic activation in the lungs

Correct Answer: Phase I hepatic metabolism followed by renal excretion

Q44. When counseling about side effects, which long-term effect should be mentioned for opioids including pentazocine?

• Permanent immunosuppression in all patients
• Risk of tolerance and physical dependence with prolonged use
• Guaranteed improvement in cognitive function
• Complete prevention of renal disease

Correct Answer: Risk of tolerance and physical dependence with prolonged use

Q45. Which of the following is a classification used to describe pentazocine’s receptor activity?

• Pure kappa antagonist
• Kappa agonist and weak mu antagonist/partial agonist
• Delta receptor superagonist
• Non-opioid analgesic

Correct Answer: Kappa agonist and weak mu antagonist/partial agonist

Q46. In pharmacology exams, an important distinguishing point of pentazocine versus morphine is:

• Pentazocine causes no constipation
• Pentazocine has kappa activity and may cause dysphoria, unlike morphine
• Morphine is a benzomorphan and pentazocine is a phenanthrene
• Both drugs are identical in mechanism and effects

Correct Answer: Pentazocine has kappa activity and may cause dysphoria, unlike morphine

Q47. Which adverse psychiatric manifestation should pharmacists warn about when dispensing pentazocine?

• Improved mood and increased sociability in all patients
• Possible dysphoria, hallucinations or confusion
• Guaranteed treatment of depression
• Immediate development of schizophrenia

Correct Answer: Possible dysphoria, hallucinations or confusion

Q48. Which factor increases the risk of pentazocine accumulation?

• Enhanced hepatic function
• Impaired renal function reducing excretion of metabolites
• High dietary fiber intake
• Concurrent use of topical emollients

Correct Answer: Impaired renal function reducing excretion of metabolites

Q49. Which monitoring advice is essential for patients stopping long-term pentazocine therapy?

• No monitoring needed; stop abruptly always
• Gradual tapering to reduce withdrawal symptoms
• Replace with high-dose benzodiazepines immediately
• Increase dose intermittently to prevent dependency

Correct Answer: Gradual tapering to reduce withdrawal symptoms

Q50. Which key study point helps distinguish pentazocine from pure opioid antagonists?

• Pentazocine blocks all opioid receptors permanently
• Pentazocine provides analgesia through agonist activity despite some antagonist properties
• Pentazocine has no analgesic effect whatsoever
• Pentazocine is identical to naloxone in function

Correct Answer: Pentazocine provides analgesia through agonist activity despite some antagonist properties

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