Inhalation anesthetics – Enflurane MCQs With Answer

Inhalation anesthetics – Enflurane MCQs With Answer

Enflurane is a volatile inhalation anesthetic important for B. Pharm students studying anesthetic agents and pharmacology. This guide covers enflurane’s mechanism of action, pharmacokinetics, metabolism to inorganic fluoride, clinical effects on the CNS, respiratory and cardiovascular systems, adverse effects including nephrotoxicity and seizure-like EEG activity, and safe clinical use. The content is keyword-rich for exam prep and pharmacy coursework, reinforcing drug interactions, contraindications, monitoring, and comparative differences with isoflurane, sevoflurane and desflurane. Clear MCQs will test your understanding of enflurane’s therapeutic profile and safety considerations. Now let’s test your knowledge with 50 MCQs on this topic.

Q1. Which class of anesthetic agents does enflurane belong to?

• Intravenous barbiturate
• Volatile halogenated ether
• Local anesthetic amide
• Opioid analgesic

Correct Answer: Volatile halogenated ether

Q2. What is the primary mechanism by which enflurane produces anesthesia?

• Activation of nicotinic acetylcholine receptors
• Inhibition of voltage-gated calcium channels only
• Enhancement of GABA-A mediated inhibition and inhibition of excitatory receptors
• Blockade of peripheral sodium channels

Correct Answer: Enhancement of GABA-A mediated inhibition and inhibition of excitatory receptors

Q3. Compared to desflurane and sevoflurane, enflurane has:

• Lower blood solubility and faster induction
• Higher blood solubility and slower induction
• Identical solubility and identical onset
• No blood solubility

Correct Answer: Higher blood solubility and slower induction

Q4. Which metabolic product of enflurane is associated with nephrotoxicity?

• Fluoride ions
• Chloride ions
• Acetaldehyde
• Trifluoroacetic acid isomers only

Correct Answer: Fluoride ions

Q5. Enflurane is known to cause which EEG-related adverse effect at high concentrations?

• Marked EEG suppression without spikes
• Seizure-like EEG activity
• Complete EEG flatline at subanesthetic doses
• No change in EEG patterns

Correct Answer: Seizure-like EEG activity

Q6. Which organ system is most directly at risk from high fluoride levels produced by enflurane metabolism?

• Cardiovascular system
• Kidneys
• Respiratory epithelium
• Pancreas

Correct Answer: Kidneys

Q7. Enflurane anesthesia typically produces which respiratory effect?

• Stimulation of respiratory drive leading to hyperventilation
• No effect on ventilation
• Dose-dependent respiratory depression
• Permanent respiratory paralysis at low doses

Correct Answer: Dose-dependent respiratory depression

Q8. Which clinical situation warrants caution or avoidance of enflurane?

• Patients with epilepsy or seizure disorder
• Patients with controlled hypertension only
• Healthy young athletes
• Superficial dermatologic surgery under local anesthesia

Correct Answer: Patients with epilepsy or seizure disorder

Q9. How does enflurane typically affect cerebral blood flow (CBF) at anesthetic concentrations?

• Decreases CBF by vasoconstriction uniformly
• Increases CBF due to cerebral vasodilation at higher doses despite metabolic depression
• No effect on CBF
• Immediately stops CBF

Correct Answer: Increases CBF due to cerebral vasodilation at higher doses despite metabolic depression

Q10. Which monitoring parameter is most important when using enflurane because of its metabolic fate?

• Serum potassium levels
• Urine output and renal function (serum creatinine)
• Blood glucose only
• Serum amylase

Correct Answer: Urine output and renal function (serum creatinine)

Q11. Enflurane is primarily eliminated from the body by:

• Hepatic metabolism only
• Renal excretion of the unchanged drug only
• Exhalation via the lungs with some hepatic metabolism
• Sweat and salivary secretion

Correct Answer: Exhalation via the lungs with some hepatic metabolism

Q12. Compared with halothane, enflurane’s cardiovascular effects are generally:

• More arrhythmogenic and highly sensitizing to catecholamines
• Less myocardial sensitization to catecholamines but still depressant
• Identical in every respect
• Only causing hypertension

Correct Answer: Less myocardial sensitization to catecholamines but still depressant

Q13. Which receptor type is commonly potentiated by enflurane to produce inhibitory effects in the CNS?

• Nicotinic acetylcholine receptors
• GABA-A receptors
• NMDA excitatory receptors
• Adrenergic alpha-1 receptors

Correct Answer: GABA-A receptors

Q14. Which adverse event is a known potential complication of enflurane related to muscle metabolism in susceptible individuals?

• Neuroleptic malignant syndrome
• Malignant hyperthermia
• Rhabdomyolysis from opioid use
• Serotonin syndrome

Correct Answer: Malignant hyperthermia

Q15. Why has clinical use of enflurane declined in favor of newer agents?

• Because enflurane is too inexpensive
• Due to concerns about fluoride-induced nephrotoxicity and slower recovery
• Because it is the fastest onset agent available
• Because it is ineffective as an anesthetic

Correct Answer: Due to concerns about fluoride-induced nephrotoxicity and slower recovery

Q16. Enflurane’s effect on systemic blood pressure is mainly due to:

• Increased cardiac output alone
• Vasodilation and myocardial depression causing hypotension
• Severe vasoconstriction raising blood pressure
• No cardiovascular effects

Correct Answer: Vasodilation and myocardial depression causing hypotension

Q17. Which patient population requires extra caution with enflurane due to altered drug handling and increased sensitivity?

• Young healthy adults only
• Patients with pre-existing renal impairment
• Patients with high muscle mass exclusively
• Patients with seasonal allergies

Correct Answer: Patients with pre-existing renal impairment

Q18. Enflurane potentiates the effects of which class of drugs commonly used during anesthesia?

• Nondepolarizing neuromuscular blockers
• Beta-blockers acting on the heart only
• Oral hypoglycemics solely
• Topical anesthetics only

Correct Answer: Nondepolarizing neuromuscular blockers

Q19. Which of the following best describes Minimum Alveolar Concentration (MAC) in relation to enflurane?

• MAC is irrelevant for inhalational agents
• MAC indicates the potency; a lower MAC means higher potency
• MAC measures renal clearance
• Enflurane has infinite MAC

Correct Answer: MAC indicates the potency; a lower MAC means higher potency

Q20. Environmental concern related to volatile anesthetics like enflurane primarily involves:

• Ozone layer formation by halogenated hydrocarbons produced in situ
• Greenhouse gas emissions and occupational exposure
• Radioactive contamination
• Heavy metal pollution

Correct Answer: Greenhouse gas emissions and occupational exposure

Q21. Which statement about enflurane metabolism is correct?

• It is completely metabolized in the gut
• It undergoes partial hepatic metabolism producing fluoride and other metabolites
• It is not metabolized and is 100% exhaled unchanged
• Metabolism occurs exclusively by renal enzymes

Correct Answer: It undergoes partial hepatic metabolism producing fluoride and other metabolites

Q22. Which clinical monitoring technique helps detect early cerebral excitability when using enflurane?

• Pulse oximetry only
• Electroencephalography (EEG)
• Urinalysis
• Stethoscope auscultation only

Correct Answer: Electroencephalography (EEG)

Q23. Enflurane’s potency relative to isoflurane is generally:

• Much higher potency than isoflurane
• Comparable but slightly less potent than isoflurane
• Completely inactive compared to isoflurane
• Only effective when injected intravenously

Correct Answer: Comparable but slightly less potent than isoflurane

Q24. Which of the following is a safe storage/handling recommendation for enflurane in a clinical pharmacy setting?

• Store in open containers near heat source
• Keep sealed, in a cool well-ventilated area and follow waste guidelines
• Dispose down the sink without precautions
• Store with flammable solvents in a crowded cabinet

Correct Answer: Keep sealed, in a cool well-ventilated area and follow waste guidelines

Q25. In the context of anesthetic depth, increasing inspired concentration of enflurane will primarily:

• Decrease alveolar concentration
• Increase alveolar and brain partial pressures, deepening anesthesia
• Only affect renal excretion
• Cause immediate immune suppression only

Correct Answer: Increase alveolar and brain partial pressures, deepening anesthesia

Q26. Which drug interaction is important to consider when enflurane is used perioperatively?

• Concurrent use of potent opioids increases ventilation
• Use with other CNS depressants increases respiratory and cardiovascular depression
• Enflurane reverses benzodiazepine effects
• Enflurane neutralizes local anesthetic toxicity

Correct Answer: Use with other CNS depressants increases respiratory and cardiovascular depression

Q27. Which adverse hepatic effect is often attributed to older volatile anesthetics and is less commonly seen with enflurane?

• Severe viral hepatitis
• Halothane-like hepatitis due to immune-mediated injury
• Acute pancreatitis
• Chronic cholangitis

Correct Answer: Halothane-like hepatitis due to immune-mediated injury

Q28. Which of the following best describes the onset and recovery profile of enflurane compared to sevoflurane?

• Enflurane has a faster onset and faster recovery than sevoflurane
• Enflurane has slower onset and slower recovery than sevoflurane
• Both have identical onset and recovery
• Enflurane causes immediate full consciousness on inhalation

Correct Answer: Enflurane has slower onset and slower recovery than sevoflurane

Q29. Which physiologic reflex is blunted by enflurane during surgical stimulation?

• Cough reflex and airway protective reflexes
• Hair growth reflex
• Gag reflex enhancement only
• Increased salivation reflex exclusively

Correct Answer: Cough reflex and airway protective reflexes

Q30. For which surgical procedure type is enflurane generally an appropriate choice historically?

• Minor dermatologic procedures under local anesthesia only
• General anesthesia for a variety of surgeries where inhalational maintenance is used
• Exclusive obstetric analgesia without monitoring
• Topical wound care

Correct Answer: General anesthesia for a variety of surgeries where inhalational maintenance is used

Q31. Which of the following statements about occupational exposure to enflurane is correct?

• There is no occupational exposure concern
• Waste anesthetic gases can pose health risks; scavenging systems are recommended
• Exposure is beneficial for staff well-being
• Enflurane exposure is only a concern in outdoor settings

Correct Answer: Waste anesthetic gases can pose health risks; scavenging systems are recommended

Q32. Which monitoring parameter is least useful when assessing the pharmacodynamic effect of enflurane?

• End-tidal anesthetic concentration
• Bispectral index (BIS) for depth of anesthesia
• Serum fluoride level in acute intraoperative decisions
• Blood pressure and heart rate

Correct Answer: Serum fluoride level in acute intraoperative decisions

Q33. Which statement about enflurane and neuromuscular blockade is true?

• Enflurane antagonizes nondepolarizing blockers
• Enflurane potentiates and prolongs the effect of neuromuscular blockers
• Enflurane has no interaction with neuromuscular blockers
• Enflurane converts nondepolarizing blockers into depolarizing agents

Correct Answer: Enflurane potentiates and prolongs the effect of neuromuscular blockers

Q34. Which of the following is a clinical sign of excessive enflurane depth?

• Hypertension and tachycardia only
• Marked hypotension, low tidal volumes, and slow respiratory rate
• Hyperreflexia with elevated consciousness
• Increased spontaneous movement and awareness

Correct Answer: Marked hypotension, low tidal volumes, and slow respiratory rate

Q35. Enflurane’s pungency compared to other agents affects which clinical aspect?

• It makes it ideal for mask induction in awake children due to pleasant smell
• Irritating odor may limit use for inhalational induction
• No relevance to clinical practice
• Promotes allergic reactions in all patients

Correct Answer: Irritating odor may limit use for inhalational induction

Q36. Which property of enflurane contributes to slower emergence from anesthesia?

• High blood/gas partition coefficient (greater solubility)
• Complete lack of solubility in blood
• Rapid hepatic clearance only
• Immediate renal elimination

Correct Answer: High blood/gas partition coefficient (greater solubility)

Q37. Which laboratory test may be most useful to monitor potential renal effects after prolonged enflurane exposure?

• Serum troponin
• Serum creatinine and urine output
• Liver function tests only
• Complete blood count only

Correct Answer: Serum creatinine and urine output

Q38. Which of the following is a distinguishing clinical comparison: enflurane vs desflurane?

• Enflurane has a faster washout than desflurane
• Desflurane has very low blood solubility and faster emergence than enflurane
• They are chemically identical and interchangeable
• Desflurane produces fluoride ions at much higher rates than enflurane

Correct Answer: Desflurane has very low blood solubility and faster emergence than enflurane

Q39. Which perioperative factor increases the risk of fluoride-associated renal injury with enflurane?

• Short duration of anesthesia under 30 minutes
• Prolonged exposure and high cumulative dose
• Use of regional anesthesia only
• Preoperative hydration optimization

Correct Answer: Prolonged exposure and high cumulative dose

Q40. Which statement about the solubility of enflurane is accurate?

• Low blood solubility leads to extremely rapid induction
• Moderate-to-high blood solubility leads to slower induction and recovery compared to modern agents
• Solubility is irrelevant to onset
• It is insoluble in both blood and fat

Correct Answer: Moderate-to-high blood solubility leads to slower induction and recovery compared to modern agents

Q41. Which of the following is an appropriate pharmacy counseling point regarding enflurane vials in the OR drug area?

• Label open bottles with date/time and store according to policy
• Leave bottles uncapped for quick access
• Mix enflurane with other agents in the same container
• Discard unused agent down the sink

Correct Answer: Label open bottles with date/time and store according to policy

Q42. Enflurane’s effect on ventilatory response to carbon dioxide is to:

• Enhance the ventilatory response to CO2
• Depress the ventilatory response to CO2
• Have no effect on CO2 sensitivity
• Reverse CO2 retention permanently

Correct Answer: Depress the ventilatory response to CO2

Q43. Which pharmacokinetic factor most influences the speed of induction with enflurane?

• Solubility in blood (blood/gas partition coefficient)
• Rate of renal excretion
• Liver enzyme induction over months
• Patient hair color

Correct Answer: Solubility in blood (blood/gas partition coefficient)

Q44. Enflurane may increase intracranial pressure (ICP) primarily by:

• Reducing cerebral blood flow
• Causing cerebral vasodilation which increases cerebral blood volume
• Direct bone marrow stimulation
• Decreasing jugular venous pressure

Correct Answer: Causing cerebral vasodilation which increases cerebral blood volume

Q45. Which patient condition is a relative contraindication for the use of enflurane?

• Well-controlled hypothyroidism
• Severe chronic kidney disease
• Uncomplicated seasonal rhinitis
• Minor elective dental extraction under local anesthesia

Correct Answer: Severe chronic kidney disease

Q46. Which characteristic of enflurane metabolism differentiates it from desflurane?

• Enflurane undergoes more hepatic metabolism producing fluoride than desflurane
• Desflurane produces no metabolites at all
• Both are metabolized identically
• Enflurane is not metabolized at all

Correct Answer: Enflurane undergoes more hepatic metabolism producing fluoride than desflurane

Q47. Which intraoperative strategy reduces the potential renal risk from fluoride with enflurane?

• Prolonged high-concentration exposure
• Minimize duration and concentration of enflurane exposure and ensure adequate hydration
• Use enflurane at maximal concentrations indefinitely
• Dehydrate the patient preoperatively

Correct Answer: Minimize duration and concentration of enflurane exposure and ensure adequate hydration

Q48. Which statement about the use of enflurane in obstetrics is true?

• Enflurane is preferred for labor analgesia without monitoring
• All volatile anesthetics including enflurane can cause uterine relaxation and may increase bleeding
• Enflurane enhances uterine contractions significantly
• Enflurane is contraindicated in all cesarean deliveries

Correct Answer: All volatile anesthetics including enflurane can cause uterine relaxation and may increase bleeding

Q49. Which statement best summarizes why pharmacology students should study enflurane?

• It is the only anesthetic used today
• Understanding enflurane teaches principles of inhalational agent pharmacokinetics, metabolism, adverse effects and clinical decision-making
• Enflurane has no educational value
• It is a common oral medication in community pharmacy

Correct Answer: Understanding enflurane teaches principles of inhalational agent pharmacokinetics, metabolism, adverse effects and clinical decision-making

Q50. Which management step is most appropriate if malignant hyperthermia is suspected during enflurane anesthesia?

• Continue enflurane and observe
• Immediately discontinue triggering agents, call for MH cart and administer dantrolene
• Give NSAIDs only
• Increase inspired enflurane concentration

Correct Answer: Immediately discontinue triggering agents, call for MH cart and administer dantrolene

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