Cyclomethycaine MCQs With Answer

Cyclomethycaine MCQs With Answer offers B.Pharm students a focused review of cyclomethycaine — a synthetic local anesthetic — covering mechanism of action, pharmacokinetics, formulation, stability, safety and clinical considerations. This set emphasizes core pharmacology concepts such as voltage‑gated sodium channel blockade, pKa and onset, lipid solubility, protein binding, hepatic metabolism, adverse effects (CNS & cardiovascular), interactions, analytical assays and regulatory aspects relevant to dosage form design. Questions are crafted to deepen understanding for practical tasks in formulation, therapeutic monitoring and toxicity management while reinforcing exam‑level facts and application. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. What is the primary molecular mechanism by which cyclomethycaine produces local anesthesia?

• Enhancement of GABAergic transmission in peripheral nerves
• Blockade of voltage‑gated sodium channels responsible for nerve impulse propagation
• Inhibition of acetylcholine release at neuromuscular junctions
• Activation of peripheral opioid receptors

Correct Answer: Blockade of voltage‑gated sodium channels responsible for nerve impulse propagation

Q2. Cyclomethycaine belongs to which chemical class of local anesthetics commonly taught in B.Pharm pharmacology?

• Ester‑type local anesthetic
• Amide‑type local anesthetic
• Synthetic opioid local anesthetic
• Quaternary ammonium neuromuscular blocker

Correct Answer: Amide‑type local anesthetic

Q3. Which physicochemical property most directly influences the onset of action of cyclomethycaine?

• High molecular weight
• pKa relative to physiological pH
• Optical isomerism
• Melting point

Correct Answer: pKa relative to physiological pH

Q4. How does increased lipid solubility of cyclomethycaine affect its clinical profile?

• Decreases potency and duration
• Increases potency and prolongs duration of action
• Has no effect on potency or duration
• Only increases toxicity without changing potency

Correct Answer: Increases potency and prolongs duration of action

Q5. High plasma protein binding of cyclomethycaine typically results in which effect?

• Faster renal elimination
• Shorter duration of action
• Prolonged duration of action due to reservoir effect
• Immediate hypersensitivity reactions

Correct Answer: Prolonged duration of action due to reservoir effect

Q6. The primary route of metabolism for an amide local anesthetic like cyclomethycaine is:

• Plasma cholinesterases
• Renal tubular hydrolysis
• Hepatic microsomal enzymatic metabolism
• Gastrointestinal hydrolysis by gut flora

Correct Answer: Hepatic microsomal enzymatic metabolism

Q7. In severe systemic toxicity from cyclomethycaine (cardiovascular collapse), which specific rescue therapy is recommended in guidelines?

• Intravenous lipid emulsion therapy
• Intramuscular epinephrine only
• High‑dose naloxone infusion
• Oral activated charcoal

Correct Answer: Intravenous lipid emulsion therapy

Q8. Adding epinephrine to a cyclomethycaine injection primarily causes which clinical effect?

• Increased systemic absorption and shorter duration
• Vasoconstriction leading to reduced systemic absorption and prolonged local effect
• Direct antagonism of sodium channel blockade
• Increased neurotoxicity at the injection site

Correct Answer: Vasoconstriction leading to reduced systemic absorption and prolonged local effect

Q9. Which patient factor most increases the risk of accumulation and toxicity of cyclomethycaine?

• Severe hepatic impairment
• Well‑controlled hypertension
• Young age (pediatric) alone without other conditions
• Topical application to intact skin

Correct Answer: Severe hepatic impairment

Q10. Concerning allergic reactions, which statement best describes ester versus amide local anesthetic differences relevant to cyclomethycaine?

• Amide anesthetics commonly produce PABA metabolites causing allergy
• Esters are more likely to cause allergic reactions due to PABA metabolites; amides are less allergenic
• Both esters and amides have identical allergy risk
• Only topical amides produce allergic responses

Correct Answer: Esters are more likely to cause allergic reactions due to PABA metabolites; amides are less allergenic

Q11. How does local tissue acidosis (for example within infected tissue) affect the efficacy of cyclomethycaine?

• Increases the non‑ionized fraction and speeds onset
• Has no effect on drug distribution
• Increases ionized fraction, reducing membrane penetration and decreasing efficacy
• Promotes hepatic clearance and shortens duration

Correct Answer: Increases ionized fraction, reducing membrane penetration and decreasing efficacy

Q12. Which analytical technique is most appropriate and routinely used for assay and stability studies of cyclomethycaine in pharmaceutical development?

• Thin layer chromatography only
• High‑performance liquid chromatography (HPLC)
• Colorimetric spot test
• Gravimetric analysis

Correct Answer: High‑performance liquid chromatography (HPLC)

Q13. Buffering a local anesthetic solution with sodium bicarbonate immediately before injection has what main effect?

• Decreases pH increasing onset time
• Inactivates the drug
• Increases the non‑ionized fraction and accelerates onset
• Precipitates the anesthetic making it unusable

Correct Answer: Increases the non‑ionized fraction and accelerates onset

Q14. Combining cyclomethycaine with epinephrine typically allows what change to the maximum safe clinical dose?

• No change; maximum dose is fixed
• Decrease maximum dose because of increased toxicity
• Increase allowable maximum dose due to reduced systemic absorption
• Eliminates need to consider patient weight

Correct Answer: Increase allowable maximum dose due to reduced systemic absorption

Q15. Regarding placental transfer, what is true about cyclomethycaine when used in obstetric regional anesthesia?

• It does not cross the placenta at all
• It crosses the placenta by passive diffusion and fetal exposure must be considered
• It is actively transported away from the fetus by placental pumps
• It is metabolized in the amniotic fluid preventing fetal exposure

Correct Answer: It crosses the placenta by passive diffusion and fetal exposure must be considered

Q16. Early central nervous system signs of cyclomethycaine systemic toxicity include which of the following?

• Hyperglycemia and polyuria
• Circumoral numbness, tinnitus and metallic taste progressing to seizures
• Profound bradycardia without prodrome
• Painless jaundice

Correct Answer: Circumoral numbness, tinnitus and metallic taste progressing to seizures

Q17. Which adjuvant added to peripheral nerve block mixtures is known to prolong block duration when used perineurally with local anesthetics like cyclomethycaine?

• Naloxone
• Dexamethasone
• Acetazolamide
• Probenecid

Correct Answer: Dexamethasone

Q18. For formulation and storage, which environmental factors most commonly affect cyclomethycaine stability?

• Presence of heavy metals only
• pH extremes and light exposure leading to degradation
• Ambient magnetic fields
• Background radio waves

Correct Answer: pH extremes and light exposure leading to degradation

Q19. Which route of administration is least appropriate for achieving local anesthesia with cyclomethycaine in clinical practice?

• Topical application to mucous membranes
• Peripheral nerve block injection
• Oral administration for systemic anesthesia
• Subcutaneous infiltration

Correct Answer: Oral administration for systemic anesthesia

Q20. Co‑administration of cyclomethycaine with other drugs that depress cardiac conduction (e.g., certain antiarrhythmics) requires caution because:

• They invariably increase renal clearance of cyclomethycaine
• They may potentiate cardiotoxic effects and conduction disturbances
• They convert cyclomethycaine into inactive metabolites
• They cause immediate hypersensitivity reactions

Correct Answer: They may potentiate cardiotoxic effects and conduction disturbances

Q21. What primary process terminates the local anesthetic effect at the nerve after infiltration?

• Local enzymatic inactivation at the nerve membrane
• Redistribution away from the nerve into the systemic circulation
• Permanent denaturation of sodium channels
• Metabolism within the extracellular matrix

Correct Answer: Redistribution away from the nerve into the systemic circulation

Q22. Why might the selection of a single enantiomer of a local anesthetic be advantageous for drugs like cyclomethycaine?

• Single enantiomer always has increased analgesic potency but more toxicity
• S‑enantiomer selection can reduce cardiotoxicity while retaining efficacy
• Enantiomer choice has no impact on toxicity or potency
• R‑enantiomers are universally preferred for all local anesthetics

Correct Answer: S‑enantiomer selection can reduce cardiotoxicity while retaining efficacy

Q23. In preformulation studies for a cyclomethycaine injectable, which parameters are essential for B.Pharm students to evaluate?

• Solubility, pKa, lipophilicity (log P), and chemical stability
• Only color and odor
• Microbial growth in raw materials only
• Particle size of dissolved molecules

Correct Answer: Solubility, pKa, lipophilicity (log P), and chemical stability

Q24. Which sample preparation technique is commonly used to isolate cyclomethycaine from plasma before chromatographic analysis?

• Direct injection of whole blood without preparation
• Solid‑phase extraction (SPE)
• Lyophilization of intact plasma only
• Visual color comparison

Correct Answer: Solid‑phase extraction (SPE)

Q25. Factors that increase the risk of local tissue and nerve toxicity with cyclomethycaine include:

• Using very low concentrations and single dose
• High concentration, repeated injections and prolonged exposure
• Mixing with sterile saline immediately before use
• Applying cold compresses after injection

Correct Answer: High concentration, repeated injections and prolonged exposure

Q26. Which nerve fiber types are typically blocked first by cyclomethycaine, correlating with loss of pain before motor function?

• Large myelinated motor fibers first
• Small myelinated pain fibers (A‑delta) followed by unmyelinated C fibers
• Proprioceptive fibers only
• Autonomic fibers exclusively

Correct Answer: Small myelinated pain fibers (A‑delta) followed by unmyelinated C fibers

Q27. Topical bioavailability of cyclomethycaine is increased under which condition?

• Intact, keratinized skin with normal barrier function
• Damaged or inflamed skin with impaired barrier
• Application to cold, vasoconstricted tissue only
• When applied together with a surfactant that prevents absorption

Correct Answer: Damaged or inflamed skin with impaired barrier

Q28. The most immediate clinical sign suggesting inadvertent intravascular injection of cyclomethycaine is usually:

• Delayed wound healing
• Rapid onset of CNS excitation such as tinnitus or seizures
• Local erythema at the injection site only
• Gradual improvement in analgesia

Correct Answer: Rapid onset of CNS excitation such as tinnitus or seizures

Q29. For regulatory submission of a generic cyclomethycaine injectable, which studies are essential to support approval?

• Bioequivalence, impurity profiling and stability studies
• Only an opinion letter from the manufacturer
• Traditional use documentation without analytical data
• Animal tests for color acceptance only

Correct Answer: Bioequivalence, impurity profiling and stability studies

Q30. Which of the following is NOT a usual therapeutic application of cyclomethycaine formulations?

• Topical anesthesia for mucosal procedures
• Peripheral nerve block for surgical anesthesia
• Intravenous infusion as a systemic analgesic for chronic pain
• Local infiltration for minor surgical procedures

Correct Answer: Intravenous infusion as a systemic analgesic for chronic pain

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