Miscellaneous anticonvulsants – Gabapentin MCQs With Answer

Miscellaneous anticonvulsants – Gabapentin MCQs With Answer

Gabapentin is a widely used miscellaneous anticonvulsant and GABA analogue essential in B.Pharm pharmacology. This concise, student-focused introduction covers gabapentin’s mechanism of action (binding the α2δ subunit of voltage‑gated calcium channels), pharmacokinetics (dose‑dependent, saturable absorption, renal excretion unchanged), clinical uses (adjunctive therapy for partial seizures, postherpetic neuralgia, neuropathic pain), dosing principles, adverse effects (dizziness, somnolence, peripheral edema), drug interactions, and renal dose adjustments. Emphasis is placed on therapeutic considerations, monitoring, and differences from pregabalin to build clinical understanding. These MCQs focus on mechanism, pharmacokinetics, dosing strategies, adverse effects, interactions, special populations (pediatrics, geriatrics, pregnancy), and clinical problem-solving to prepare you for exams and pharmacy practice. Now let’s test your knowledge with 50 MCQs on this topic.

Q1. Which best describes gabapentin’s primary mechanism of action?

• Enhancement of GABA-A receptor activity
• Inhibition of monoamine oxidase
• Binding to the α2δ subunit of voltage‑gated calcium channels
• Blocking NMDA receptors

Correct Answer: Binding to the α2δ subunit of voltage‑gated calcium channels

Q2. Gabapentin is chemically classified as which of the following?

• A benzodiazepine derivative
• A barbiturate
• A cyclic GABA analogue
• A succinimide

Correct Answer: A cyclic GABA analogue

Q3. Which of the following is an FDA‑approved indication for gabapentin?

• Generalized tonic‑clonic seizures as monotherapy in adults
• Postherpetic neuralgia
• Acute migraine attack
• Parkinson’s disease motor symptoms

Correct Answer: Postherpetic neuralgia

Q4. Which pharmacokinetic property is characteristic of gabapentin absorption?

• Linear absorption with dose
• Saturable, dose‑dependent absorption causing decreased bioavailability at high doses
• Extensive first‑pass hepatic metabolism
• Absorption only when taken with a high‑fat meal

Correct Answer: Saturable, dose‑dependent absorption causing decreased bioavailability at high doses

Q5. How is gabapentin primarily eliminated from the body?

• Hepatic metabolism to active metabolites
• Renal excretion of unchanged drug
• Biliary excretion after conjugation
• Pulmonary excretion

Correct Answer: Renal excretion of unchanged drug

Q6. What is a common central nervous system adverse effect of gabapentin?

• Hypertension
• Dizziness and somnolence
• Excessive lacrimation
• Tremor only during exertion

Correct Answer: Dizziness and somnolence

Q7. Which statement about gabapentin and protein binding is correct?

• Gabapentin is highly protein bound (>95%)
• Gabapentin has moderate protein binding (~50%)
• Gabapentin has negligible protein binding
• Protein binding is variable and unpredictable

Correct Answer: Gabapentin has negligible protein binding

Q8. The approximate elimination half‑life of gabapentin in subjects with normal renal function is:

• 30–50 hours
• 5–7 hours
• 1–2 hours
• 72 hours

Correct Answer: 5–7 hours

Q9. Which dosing consideration is most important for gabapentin?

• No adjustment needed in renal impairment
• Adjust dose according to renal function
• Reduce dose in hepatic impairment only
• Always give as single daily dose due to long half‑life

Correct Answer: Adjust dose according to renal function

Q10. Which of the following drugs significantly reduces gabapentin absorption if taken concurrently?

• Proton pump inhibitors
• Antacids containing aluminium and magnesium
• Statins
• Oral contraceptives

Correct Answer: Antacids containing aluminium and magnesium

Q11. Gabapentin’s Tmax (time to peak plasma concentration) after oral dosing is approximately:

• 15–30 minutes
• 2–3 hours
• 12–24 hours
• 48 hours

Correct Answer: 2–3 hours

Q12. Which formulation is a prodrug of gabapentin designed for extended absorption?

• Gabapentin immediate‑release capsules
• Gabapentin enacarbil
• Pregabalin
• Gabapentin topical gel

Correct Answer: Gabapentin enacarbil

Q13. Compared to pregabalin, gabapentin generally shows:

• Linear pharmacokinetics and higher potency
• Saturable absorption and non‑linear bioavailability
• Greater protein binding than pregabalin
• Exclusive hepatic metabolism unlike pregabalin

Correct Answer: Saturable absorption and non‑linear bioavailability

Q14. Which monitoring parameter is most relevant during long‑term gabapentin therapy?

• Liver function tests monthly
• Serum eGFR or creatinine periodically
• Serum drug concentration routinely
• Routine ECG every 6 months

Correct Answer: Serum eGFR or creatinine periodically

Q15. For neuropathic pain, gabapentin’s clinical benefit typically appears:

• Immediately within minutes
• Within hours after the first dose
• Over days to weeks with titration
• Only after several months

Correct Answer: Over days to weeks with titration

Q16. Which statement about gabapentin and hepatic impairment is correct?

• Gabapentin requires marked dose reduction in mild hepatic impairment
• Hepatic metabolism increases gabapentin clearance
• Hepatic impairment generally does not necessitate dose adjustment because gabapentin is not extensively metabolized
• Gabapentin is contraindicated in hepatic impairment

Correct Answer: Hepatic impairment generally does not necessitate dose adjustment because gabapentin is not extensively metabolized

Q17. A major safety concern when gabapentin is combined with opioids is:

• Increased risk of serotonin syndrome
• Additive CNS and respiratory depression
• Severe hepatotoxicity
• Antagonism reducing opioid efficacy

Correct Answer: Additive CNS and respiratory depression

Q18. Which adverse effect is especially important to counsel elderly patients about?

• Renal stones
• Falls due to dizziness and ataxia
• Hyperactivity and insomnia
• Blue‑green skin discoloration

Correct Answer: Falls due to dizziness and ataxia

Q19. Abrupt discontinuation of gabapentin can cause which of the following?

• Hypertensive crisis
• Withdrawal seizures and increased seizure frequency
• Immediate resolution of neuropathic pain
• Permanent liver failure

Correct Answer: Withdrawal seizures and increased seizure frequency

Q20. Which statement about therapeutic drug monitoring (TDM) of gabapentin is correct?

• TDM is routinely required to adjust therapy
• TDM is rarely helpful; clinical response and renal function guide dosing
• Serum levels directly correlate with efficacy and must be kept above a specific threshold
• TDM prevents all adverse effects

Correct Answer: TDM is rarely helpful; clinical response and renal function guide dosing

Q21. Which is the common brand name for gabapentin?

• Lyrica
• Neurontin
• Lamictal
• Topamax

Correct Answer: Neurontin

Q22. Gabapentin is most effective as which type of antiepileptic agent?

• Primary monotherapy for absence seizures
• Adjunctive therapy for partial (focal) seizures
• First‑line treatment for status epilepticus
• Only for generalized myoclonic seizures

Correct Answer: Adjunctive therapy for partial (focal) seizures

Q23. Which off‑label use is commonly associated with gabapentin?

• Type 2 diabetes treatment
• Treatment of neuropathic pain such as diabetic neuropathy and fibromyalgia
• Curative therapy for multiple sclerosis
• Antibacterial therapy

Correct Answer: Treatment of neuropathic pain such as diabetic neuropathy and fibromyalgia

Q24. Which pharmacokinetic feature distinguishes pregabalin from gabapentin?

• Pregabalin has saturable absorption like gabapentin
• Pregabalin shows linear pharmacokinetics and higher bioavailability
• Pregabalin is extensively hepatically metabolized while gabapentin is not
• Pregabalin is eliminated via bile primarily

Correct Answer: Pregabalin shows linear pharmacokinetics and higher bioavailability

Q25. Which clinical population requires careful dose adjustment of gabapentin?

• Patients with normal renal function
• Patients with renal impairment or on dialysis
• Patients with mild eczema
• Athletes after training

Correct Answer: Patients with renal impairment or on dialysis

Q26. Which counseling point is appropriate for gabapentin dosing frequency?

• Administer once daily at bedtime only
• Divide doses (e.g., TID) because of relatively short half‑life
• Take only when seizure occurs
• Use an inhaled formulation for faster onset

Correct Answer: Divide doses (e.g., TID) because of relatively short half‑life

Q27. Which lab test is most useful to guide gabapentin dose adjustments?

• Liver enzymes (AST/ALT)
• Serum creatinine and estimated GFR
• Plasma albumin concentration
• Serum potassium level

Correct Answer: Serum creatinine and estimated GFR

Q28. Which adverse effect, though less common, has been reported with gabapentin and other antiepileptics?

• Increased incidence of suicidal ideation
• Marked hyperglycemia
• Ototoxicity leading to deafness
• Severe hemolytic anemia

Correct Answer: Increased incidence of suicidal ideation

Q29. In pregnancy, gabapentin is classified historically as which category?

• Category A
• Category B
• Category C
• Category X

Correct Answer: Category C

Q30. Which of the following best explains why gabapentin is not considered a direct GABA receptor agonist?

• It increases GABA synthesis directly in neurons
• It structurally mimics GABA but does not bind GABA receptors and acts mainly on calcium channels
• It blocks GABA uptake transporters exclusively
• It is metabolized to benzodiazepines

Correct Answer: It structurally mimics GABA but does not bind GABA receptors and acts mainly on calcium channels

Q31. Which is a common starting regimen for adult gabapentin therapy for neuropathic pain?

• 300 mg once weekly
• 300 mg once daily, titrating to 300 mg three times daily
• 50 mg single dose daily
• 4000 mg once at bedtime

Correct Answer: 300 mg once daily, titrating to 300 mg three times daily

Q32. Which statement about gabapentin and food is most accurate?

• Food drastically reduces gabapentin absorption and must be avoided
• Food has minimal clinically significant effect on gabapentin exposure
• Gabapentin must be taken with a high‑fat meal to be absorbed
• Gabapentin is unstable in the gastrointestinal tract unless taken with food

Correct Answer: Food has minimal clinically significant effect on gabapentin exposure

Q33. Which symptom could indicate gabapentin overdose?

• Marked agitation and hypertension only
• Profound sedation, ataxia, and respiratory depression
• Severe hyperthermia only
• Immediate cardiac arrest in all cases

Correct Answer: Profound sedation, ataxia, and respiratory depression

Q34. Which transport mechanism mediates gabapentin intestinal absorption?

• Sodium‑dependent glucose transporter
• L‑amino acid transport system (saturable transporter)
• Simple passive diffusion only
• P‑glycoprotein efflux pump exclusively

Correct Answer: L‑amino acid transport system (saturable transporter)

Q35. Which clinical scenario would most likely require immediate gabapentin dose reduction?

• New onset mild rash with no systemic signs
• Acute renal failure with marked reduction in eGFR
• Transient headache after starting therapy
• Improved seizure control

Correct Answer: Acute renal failure with marked reduction in eGFR

Q36. Compared to gabapentin, pregabalin is:

• Less orally bioavailable and highly variable
• More potent with linear kinetics and higher bioavailability
• Exclusively administered intravenously
• Eliminated by hepatic metabolism to multiple metabolites

Correct Answer: More potent with linear kinetics and higher bioavailability

Q37. Which adverse metabolic effect is commonly associated with long‑term gabapentin use?

• Severe hypercholesterolemia
• Weight gain and peripheral edema in some patients
• Marked hypoglycemia
• Hyperthyroidism

Correct Answer: Weight gain and peripheral edema in some patients

Q38. Which best describes gabapentin’s usefulness in treating status epilepticus?

• First‑line agent in intravenous bolus form
• Not appropriate for acute management of status epilepticus
• Preferred over benzodiazepines for rapid control
• Only effective when given intramuscularly

Correct Answer: Not appropriate for acute management of status epilepticus

Q39. In patients on dialysis, gabapentin dosing should be:

• Unchanged regardless of dialysis schedule
• Given only after dialysis sessions with supplemental dosing as needed
• Switched to intravenous form during dialysis
• Stopped permanently

Correct Answer: Given only after dialysis sessions with supplemental dosing as needed

Q40. Which neurological sign should prompt dose review when a patient is on gabapentin?

• Improved coordination
• New or worsening ataxia and gait disturbance
• Slight increase in appetite only
• Clear speech without slurring

Correct Answer: New or worsening ataxia and gait disturbance

Q41. Which statement is true regarding gabapentin use in pediatrics?

• It is never used in children
• Pediatric dosing is weight‑based and requires careful titration
• Children metabolize gabapentin into active neurosteroids, increasing effect
• No safety data exist for any pediatric age group

Correct Answer: Pediatric dosing is weight‑based and requires careful titration

Q42. Which interaction is clinically relevant with gabapentin?

• Strong CYP3A4 inducers dramatically lower gabapentin levels
• Antacids reduce gabapentin absorption if taken concurrently
• Warfarin levels are substantially increased by gabapentin
• Gabapentin increases metabolism of oral contraceptives

Correct Answer: Antacids reduce gabapentin absorption if taken concurrently

Q43. Which is a correct statement about gabapentin and breastfeeding?

• Gabapentin is not excreted in breast milk at all
• Gabapentin is excreted in breast milk; assess risks and benefits before use
• Breastfeeding is absolutely contraindicated with any gabapentin exposure
• Gabapentin enhances lactation significantly

Correct Answer: Gabapentin is excreted in breast milk; assess risks and benefits before use

Q44. Which clinical pearl is important when switching a patient from gabapentin to pregabalin?

• No titration needed; start full pregabalin dose immediately
• Pregabalin is more potent; use an appropriate conversion and titration strategy
• Pregabalin is less effective and should be avoided
• Both drugs cannot be used sequentially due to cross‑reactive metabolites

Correct Answer: Pregabalin is more potent; use an appropriate conversion and titration strategy

Q45. Which patient report should prompt consideration of dose reduction or discontinuation of gabapentin?

• Occasional mild dry mouth
• New onset severe depression or suicidal thoughts
• Minor transient rash that resolves
• Improved seizure control with mild sedation only

Correct Answer: New onset severe depression or suicidal thoughts

Q46. Which statement about gabapentin’s hepatic drug interactions is correct?

• Gabapentin induces CYP enzymes and lowers levels of many drugs
• Gabapentin is primarily renally excreted and has minimal CYP‑mediated drug interactions
• Gabapentin is a strong CYP3A4 inhibitor
• Gabapentin is extensively metabolized by CYP2D6

Correct Answer: Gabapentin is primarily renally excreted and has minimal CYP‑mediated drug interactions

Q47. Which formulation of gabapentin improves compliance with less frequent dosing?

• Immediate‑release gabapentin only
• Gabapentin enacarbil (prodrug) extended‑release formulation
• Intravenous gabapentin weekly
• Topical gabapentin patch

Correct Answer: Gabapentin enacarbil (prodrug) extended‑release formulation

Q48. Which clinical effect best explains gabapentin’s utility in neuropathic pain?

• Direct blockade of peripheral sodium channels exclusively
• Reduction of excitatory neurotransmitter release via diminished presynaptic calcium influx
• Increasing dopamine release in the spinal cord
• Neutralizing antibodies against pain mediators

Correct Answer: Reduction of excitatory neurotransmitter release via diminished presynaptic calcium influx

Q49. Which adverse effect is a recognized respiratory risk when gabapentin is combined with other CNS depressants?

• Asthma exacerbation unrelated to sedation
• Life‑threatening respiratory depression
• Bronchospasm due to histamine release
• Chronic cough development

Correct Answer: Life‑threatening respiratory depression

Q50. Which counseling point should be given about driving or operating machinery while taking gabapentin?

• It has no CNS effects; no precautions needed
• Avoid driving until you know how gabapentin affects you due to dizziness and somnolence
• Driving is prohibited permanently while on gabapentin
• Only operate machinery immediately after the highest dose of the day

Correct Answer: Avoid driving until you know how gabapentin affects you due to dizziness and somnolence

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