Tetracaine MCQs With Answer

Tetracaine MCQs With Answer — This concise, targeted set of practice questions is designed for B. Pharm students to master tetracaine pharmacology, mechanism of action, metabolism, clinical uses, toxicity, dosing and contraindications. Emphasis is on tetracaine as an ester-type local anesthetic: sodium channel blockade, plasma esterase hydrolysis, PABA-related allergy, onset/duration, lipid solubility, protein binding, systemic and cardiovascular toxicity, neuraxial and topical applications, drug interactions and special population considerations. Each question reinforces key concepts relevant to therapeutics, formulation and safe clinical use. Use these MCQs to deepen understanding and prepare for exams and practical dispensing. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. Which chemical class does tetracaine belong to?

• Ester-type local anesthetic
• Amide-type local anesthetic
• Opioid analgesic
• Alpha-2 agonist

Correct Answer: Ester-type local anesthetic

Q2. What is the primary mechanism of action of tetracaine?

• Activation of GABA receptors
• Blockade of voltage-gated sodium channels
• Inhibition of cyclooxygenase enzymes
• Antagonism of NMDA receptors

Correct Answer: Blockade of voltage-gated sodium channels

Q3. Which enzyme system primarily metabolizes tetracaine?

• Hepatic cytochrome P450 enzymes
• Plasma cholinesterases (butyrylcholinesterase)
• Monoamine oxidase
• Renal brush-border peptidases

Correct Answer: Plasma cholinesterases (butyrylcholinesterase)

Q4. Hypersensitivity to tetracaine is most commonly related to formation of which metabolite?

• Acetylsalicylic acid
• Para-aminobenzoic acid (PABA)
• Nitrosoamine
• Sulfate conjugate

Correct Answer: Para-aminobenzoic acid (PABA)

Q5. Compared with procaine, tetracaine is generally:

• Less potent and shorter acting
• More potent and longer acting
• Identical in potency and duration
• Only used intravenously

Correct Answer: More potent and longer acting

Q6. Which statement best describes tetracaine’s onset and duration of action?

• Rapid onset and short duration
• Slow onset and long duration
• Rapid onset and ultra-long duration
• No anesthetic effect without adrenaline

Correct Answer: Slow onset and long duration

Q7. Tetracaine is commonly used in which clinical application?

• Topical ophthalmic anesthesia
• Oral systemic analgesia
• Chronic neuropathic pain patches
• First-line antipyretic

Correct Answer: Topical ophthalmic anesthesia

Q8. The classic sequence of systemic toxicity from local anesthetics like tetracaine involves:

• Cardiac arrest followed by CNS excitation
• CNS excitation followed by CNS depression and cardiovascular collapse
• Immediate renal failure
• Peripheral neuropathy without central symptoms

Correct Answer: CNS excitation followed by CNS depression and cardiovascular collapse

Q9. Which additive is commonly used to decrease systemic absorption of tetracaine at the injection site?

• Sodium bicarbonate
• Epinephrine (adrenaline)
• Probenecid
• Acetaminophen

Correct Answer: Epinephrine (adrenaline)

Q10. A contraindication to tetracaine use is:

• Known hypersensitivity to ester local anesthetics
• Controlled hypertension
• Mild seasonal allergy to pollen
• Corrected hypothyroidism

Correct Answer: Known hypersensitivity to ester local anesthetics

Q11. How does a high pKa of a local anesthetic like tetracaine affect its clinical onset?

• Higher pKa leads to faster onset
• Higher pKa leads to slower onset
• pKa has no effect on onset
• Higher pKa increases systemic clearance

Correct Answer: Higher pKa leads to slower onset

Q12. In infected or acidic tissue, the efficacy of tetracaine is reduced because:

• Protein binding is increased
• More drug is ionized and cannot penetrate nerves
• Plasma cholinesterase activity is increased
• The pH increases, causing degradation

Correct Answer: More drug is ionized and cannot penetrate nerves

Q13. Cross-reactivity in allergic reactions is most likely between tetracaine and which group?

• Other ester local anesthetics
• Amide local anesthetics like lidocaine
• NSAIDs
• Beta-blockers

Correct Answer: Other ester local anesthetics

Q14. Which pharmacokinetic property is most closely associated with increased potency and longer duration of tetracaine?

• Low lipid solubility
• High protein binding and lipid solubility
• Rapid renal excretion
• Minimal plasma binding

Correct Answer: High protein binding and lipid solubility

Q15. Is tetracaine used for spinal (subarachnoid) anesthesia in clinical practice?

• Yes, it can be used for spinal anesthesia
• No, it is contraindicated for spinal use
• Only used intravenously
• Only used as an oral agent

Correct Answer: Yes, it can be used for spinal anesthesia

Q16. Which specific plasma enzyme deficiency would prolong tetracaine effect?

• Carnitine acyltransferase deficiency
• Butyrylcholinesterase (pseudocholinesterase) deficiency
• Acetyl-CoA carboxylase deficiency
• Glucose-6-phosphate dehydrogenase deficiency

Correct Answer: Butyrylcholinesterase (pseudocholinesterase) deficiency

Q17. Administration of cholinesterase inhibitors (e.g., neostigmine) alongside tetracaine is likely to cause:

• Faster metabolism of tetracaine
• Prolonged duration and increased risk of toxicity
• No interaction
• Immediate reversal of anesthesia

Correct Answer: Prolonged duration and increased risk of toxicity

Q18. The most dangerous cause of sudden systemic toxicity during local anesthetic administration is:

• Inadvertent intravascular injection
• Topical application to intact skin
• Concurrent use of mild analgesics
• Application to a scarred joint

Correct Answer: Inadvertent intravascular injection

Q19. Which strategy prolongs the duration of action of tetracaine at the site of administration?

• Co-administration with sodium bicarbonate
• Addition of epinephrine to cause vasoconstriction
• Heating the solution to body temperature
• Diluting with large volumes of saline

Correct Answer: Addition of epinephrine to cause vasoconstriction

Q20. Common pharmaceutical formulations of tetracaine include:

• Topical solutions, gels, ointments and spinal solutions
• Oral tablets and chewable syrup
• Long-acting transdermal patches only
• Intranasal corticosteroid combinations

Correct Answer: Topical solutions, gels, ointments and spinal solutions

Q21. In severe local anesthetic systemic toxicity from tetracaine, a recommended treatment is:

• Oral activated charcoal
• Intravenous lipid emulsion therapy (lipid rescue)
• Immediate hemodialysis
• Subcutaneous epinephrine alone

Correct Answer: Intravenous lipid emulsion therapy (lipid rescue)

Q22. The order of nerve fiber blockade by tetracaine typically results in loss of:

• Motor function before pain perception
• Pain and temperature before touch and motor
• Vibration sense before pain
• Autonomic function last

Correct Answer: Pain and temperature before touch and motor

Q23. The high potency of tetracaine is primarily due to:

• High water solubility
• High lipid solubility enabling membrane penetration
• Strong affinity for opioid receptors
• Enzymatic activation in tissues

Correct Answer: High lipid solubility enabling membrane penetration

Q24. Regarding use in pregnancy, tetracaine:

• Does not cross the placenta and is safe without restriction
• Crosses the placenta and should be used with caution
• Is a known teratogen and absolutely contraindicated
• Is indicated for routine systemic analgesia in pregnancy

Correct Answer: Crosses the placenta and should be used with caution

Q25. Local anesthetics like tetracaine preferentially bind to which state of sodium channels?

• Resting (closed) state only
• Open and inactivated states, with preference for inactivated
• Only the permanently denatured channel
• Sodium channels are not their target

Correct Answer: Open and inactivated states, with preference for inactivated

Q26. Which clinical condition predisposes to prolonged effect of tetracaine due to reduced metabolism?

• Congenital pseudocholinesterase deficiency
• Hyperthyroidism
• Dehydration from mild exercise
• Early pregnancy only

Correct Answer: Congenital pseudocholinesterase deficiency

Q27. Tetracaine is chemically characterized as:

• An amide linked anesthetic
• An ester derivative commonly related to PABA
• A peptide local anesthetic
• A benzodiazepine analog

Correct Answer: An ester derivative commonly related to PABA

Q28. Mixing tetracaine with a strongly alkaline solution is likely to:

• Stabilize the ester linkage and increase potency
• Cause hydrolysis and inactivation of the drug
• Convert it into an amide anesthetic
• Have no chemical effect

Correct Answer: Cause hydrolysis and inactivation of the drug

Q29. On the cardiovascular system, systemic overdose of tetracaine typically causes:

• Significant vasodilation and negative inotropy leading to hypotension
• Marked hypertension and tachycardia only
• Isolated peripheral edema without blood pressure change
• Selective increase in renal perfusion only

Correct Answer: Significant vasodilation and negative inotropy leading to hypotension

Q30. During administration of tetracaine, which monitoring and preparedness is essential?

• No monitoring is required for topical use
• Continuous cardiovascular and respiratory monitoring with resuscitation equipment available
• Only blood glucose monitoring is necessary
• Only outpatient follow-up is sufficient

Correct Answer: Continuous cardiovascular and respiratory monitoring with resuscitation equipment available

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