Flurobuterophenones – Risperidone MCQs With Answer
This focused introduction for B. Pharm students reviews flurobuterophenones and risperidone, emphasizing pharmacology, mechanism of action, pharmacokinetics, clinical uses, adverse effects, and therapeutic monitoring. You will explore how fluorinated butyrophenone analogs influence receptor binding and CNS penetration, while risperidone’s dual antagonism at D2 and 5-HT2A receptors underpins its atypical antipsychotic profile. Key topics include metabolism (CYP2D6 and formation of 9-hydroxyrisperidone), depot formulations, EPS versus metabolic risks, drug interactions, and patient-specific dosing. Concepts are presented at a B. Pharm level to aid exam preparation and clinical understanding. Now let’s test your knowledge with 50 MCQs on this topic.
Q1. What class of compounds do flurobuterophenones most closely relate to?
- Typical benzodiazepines
- Butyrophenone antipsychotics
- Tricyclic antidepressants
- Selective serotonin reuptake inhibitors
Correct Answer: Butyrophenone antipsychotics
Q2. Risperidone is best classified as which type of antipsychotic?
- Typical (first-generation) antipsychotic
- Atypical (second-generation) antipsychotic
- Monoamine oxidase inhibitor
- Partial dopamine agonist only
Correct Answer: Atypical (second-generation) antipsychotic
Q3. The primary pharmacological mechanism of risperidone involves antagonism at which receptors?
- D2 and 5-HT2A receptors
- NMDA and GABA-A receptors
- M1 muscarinic and H2 receptors
- Beta-adrenergic and alpha-2 receptors
Correct Answer: D2 and 5-HT2A receptors
Q4. Which hepatic enzyme is mainly responsible for metabolizing risperidone to 9-hydroxyrisperidone?
- CYP3A4
- CYP2D6
- CYP1A2
- CYP2C19
Correct Answer: CYP2D6
Q5. 9-Hydroxyrisperidone is pharmacologically important because it is:
- An inactive elimination product
- A toxic impurity from synthesis
- An active metabolite (paliperidone)
- A prodrug requiring activation in gut flora
Correct Answer: An active metabolite (paliperidone)
Q6. Compared with typical butyrophenones like haloperidol, risperidone has:
- Higher risk of EPS and lower metabolic risk
- Lower D2 antagonism and more 5-HT2A antagonism
- No effect on serotonin receptors
- Only peripheral activity and no CNS effects
Correct Answer: Lower D2 antagonism and more 5-HT2A antagonism
Q7. Which clinical indication is NOT a common FDA-approved use of risperidone?
- Schizophrenia
- Bipolar mania
- Irritability associated with autism
- Chronic neuropathic pain
Correct Answer: Chronic neuropathic pain
Q8. A clinically important adverse effect of risperidone related to D2 blockade in the tuberoinfundibular pathway is:
- Hyponatremia
- Hyperprolactinemia
- Hypokalemia
- Metabolic acidosis
Correct Answer: Hyperprolactinemia
Q9. Which side effect is risperidone less likely to cause compared with clozapine?
- Agranulocytosis
- Weight gain
- Metabolic syndrome
- Sialorrhea
Correct Answer: Agranulocytosis
Q10. Which of the following is a depot (long-acting injectable) formulation of risperidone?
- Risperdal Consta
- Paliperidone palmitate
- Risperidone oral melt
- Risperdal Sublingual Spray
Correct Answer: Risperdal Consta
Q11. Before initiating Risperdal Consta (long-acting injection), best practice requires:
- Assessing oral tolerability with risperidone
- Immediate switch without testing
- Only renal function testing
- Co-administration of lithium for 2 weeks
Correct Answer: Assessing oral tolerability with risperidone
Q12. Which adverse effect is primarily mediated by alpha-1 adrenergic blockade with risperidone?
- Excessive salivation
- Orthostatic hypotension
- Urinary retention
- Hyperthermia
Correct Answer: Orthostatic hypotension
Q13. Which receptor blockade contributes most to sedation seen with risperidone?
- Muscarinic M3 receptor
- Histamine H1 receptor
- Dopamine D1 receptor
- GABA-B receptor
Correct Answer: Histamine H1 receptor
Q14. A common monitoring parameter for metabolic adverse effects of risperidone is:
- Serum amylase
- Fasting blood glucose and lipid profile
- Serum lactate dehydrogenase
- Urine osmolality
Correct Answer: Fasting blood glucose and lipid profile
Q15. Which drug interaction will likely increase risperidone plasma levels?
- CYP2D6 inhibitor such as fluoxetine
- CYP1A2 inducer such as smoking
- CYP3A4 inducer such as carbamazepine
- Gastric antacid use
Correct Answer: CYP2D6 inhibitor such as fluoxetine
Q16. In patients with significant renal impairment, risperidone use requires caution because:
- The active metabolite is primarily renally excreted
- Risperidone is entirely eliminated via bile
- It causes irreversible renal tubular necrosis
- It is converted to nephrotoxic compounds in kidney
Correct Answer: The active metabolite is primarily renally excreted
Q17. Which movement disorder is an acute extrapyramidal side effect that can occur early in risperidone therapy?
- Tardive dyskinesia
- Acute dystonia
- Parkinson’s disease
- Myasthenia gravis
Correct Answer: Acute dystonia
Q18. Compared to classical butyrophenones, fluorination in flurobuterophenones generally:
- Decreases CNS penetration substantially
- Increases lipophilicity and may alter receptor affinity
- Eliminates all dopamine receptor activity
- Makes the compound a peptide
Correct Answer: Increases lipophilicity and may alter receptor affinity
Q19. Which metabolic enzyme phenotype would likely lead to higher risperidone exposure?
- Extensive metabolizer of CYP2D6
- Poor metabolizer of CYP2D6
- Ultra-rapid CYP3A4 metabolizer
- High activity of CYP1A2
Correct Answer: Poor metabolizer of CYP2D6
Q20. Which adverse effect is most associated with long-term dopamine D2 blockade by antipsychotics including risperidone?
- Neuroleptic malignant syndrome
- Tardive dyskinesia
- Acute pancreatitis
- Hypothyroidism
Correct Answer: Tardive dyskinesia
Q21. Which population carries a boxed warning for increased mortality when treated with antipsychotics like risperidone?
- Pregnant women
- Children under 5 years
- Elderly patients with dementia-related psychosis
- Patients with diabetes
Correct Answer: Elderly patients with dementia-related psychosis
Q22. Which lab test is most appropriate when a patient on risperidone reports galactorrhea?
- Serum prolactin
- Serum potassium
- Thyroid-stimulating hormone only
- Serum creatine kinase
Correct Answer: Serum prolactin
Q23. Which adverse effect profile distinguishes atypical antipsychotics like risperidone from typical ones?
- Higher EPS, lower metabolic effects
- Lower EPS, higher metabolic effects
- Complete absence of extrapyramidal symptoms
- Exclusive cholinergic side effects
Correct Answer: Lower EPS, higher metabolic effects
Q24. Which receptor’s antagonism by risperidone can help reduce negative symptoms of schizophrenia?
- Alpha-2 adrenergic receptor
- 5-HT2A serotonin receptor
- NMDA receptor
- Opioid mu receptor
Correct Answer: 5-HT2A serotonin receptor
Q25. Which clinical sign suggests neuroleptic malignant syndrome in a patient on risperidone?
- Bradycardia and hypothermia
- Hyperthermia, muscle rigidity, and autonomic instability
- Isolated dry mouth only
- Gradual weight loss over months
Correct Answer: Hyperthermia, muscle rigidity, and autonomic instability
Q26. Risperidone’s minimal anticholinergic activity implies which clinical consequence?
- High incidence of urinary retention
- Lower risk of cognitive impairment due to antimuscarinic effects
- Marked mydriasis and severe constipation
- Frequent anticholinergic delirium in elderly
Correct Answer: Lower risk of cognitive impairment due to antimuscarinic effects
Q27. Which effect is commonly monitored as part of cardiovascular safety with risperidone?
- QT interval prolongation on ECG
- Elevated serum amylase
- Increased creatinine clearance
- Serum iron levels
Correct Answer: QT interval prolongation on ECG
Q28. Which statement about risperidone dosing in children is true?
- Dosing is identical to adults regardless of weight
- Lower weight-adjusted doses and careful titration are recommended
- Risperidone is contraindicated in all pediatric patients
- No monitoring is necessary in children
Correct Answer: Lower weight-adjusted doses and careful titration are recommended
Q29. Which adverse metabolic change is most associated with long-term risperidone therapy?
- Decreased triglycerides
- Weight gain and dyslipidemia
- Severe hypoglycemia
- Hypolipidemia
Correct Answer: Weight gain and dyslipidemia
Q30. In case of acute severe agitation on risperidone therapy, the immediate management includes:
- High-dose oral risperidone only
- Supportive care, sedation (e.g., benzodiazepines) and monitoring
- Forced dialysis
- Administration of MAO inhibitors
Correct Answer: Supportive care, sedation (e.g., benzodiazepines) and monitoring
Q31. Which clinical feature differentiates tardive dyskinesia from acute dystonia?
- Tardive dyskinesia is rapid onset within hours
- Tardive dyskinesia is typically late-onset and often irreversible
- Acute dystonia develops after months to years only
- They are clinically identical and indistinguishable
Correct Answer: Tardive dyskinesia is typically late-onset and often irreversible
Q32. Which property of flurobuterophenones can alter pharmacodynamic behavior compared with non-fluorinated analogs?
- Decreased receptor binding entirely
- Altered electronic distribution influencing receptor affinity
- Conversion into peptides in vivo
- Complete resistance to hepatic metabolism
Correct Answer: Altered electronic distribution influencing receptor affinity
Q33. Which monitoring is most appropriate when risperidone causes significant weight gain?
- Bone mineral density scan monthly
- Fasting glucose, HbA1c and lipid profile
- Serum amylase weekly
- Serum magnesium levels
Correct Answer: Fasting glucose, HbA1c and lipid profile
Q34. Which statement about risperidone and pregnancy is most accurate?
- Risperidone is entirely safe and requires no monitoring during pregnancy
- Use only if benefit justifies potential fetal risk; neonates may show EPS or withdrawal
- Administer double the usual dose in pregnancy for efficacy
- Risperidone is contraindicated in all reproductive-age women
Correct Answer: Use only if benefit justifies potential fetal risk; neonates may show EPS or withdrawal
Q35. Which receptor interaction of risperidone is most implicated in weight gain?
- 5-HT1A agonism
- H1 histamine and 5-HT2C antagonism
- D1 receptor partial agonism
- Muscarinic M2 agonism
Correct Answer: H1 histamine and 5-HT2C antagonism
Q36. Which statement about therapeutic drug monitoring (TDM) of risperidone is true?
- TDM is routinely required for all patients
- TDM can be useful in suspected noncompliance or drug interactions but is not routine
- TDM determines liver enzyme genotype directly
- TDM replaces clinical monitoring of side effects
Correct Answer: TDM can be useful in suspected noncompliance or drug interactions but is not routine
Q37. When combined with strong CYP2D6 inhibitors, risperidone dose adjustment is:
- Not necessary since it is not metabolized by CYP2D6
- Often required to avoid increased plasma levels and side effects
- Always doubled to maintain efficacy
- Only adjusted if combined with CYP3A4 inducers
Correct Answer: Often required to avoid increased plasma levels and side effects
Q38. Which antipsychotic would typically be preferred in Parkinson’s disease psychosis to minimize worsening motor symptoms?
- Risperidone
- Haloperidol
- Clozapine or quetiapine
- Fluoro-butyrophenone
Correct Answer: Clozapine or quetiapine
Q39. Which statement best explains why risperidone may cause less EPS at low-to-moderate doses?
- It has higher affinity for D2 than 5-HT2A
- Balanced antagonism at 5-HT2A reduces motor pathway D2 blockade impact
- It does not cross the blood–brain barrier
- It exclusively targets peripheral dopamine receptors
Correct Answer: Balanced antagonism at 5-HT2A reduces motor pathway D2 blockade impact
Q40. Which adverse event should prompt immediate discontinuation and emergency evaluation in a patient on risperidone?
- Mild transient headache
- High fever, severe rigidity and autonomic instability
- Minor transient dizziness on standing
- Gradual weight gain over months
Correct Answer: High fever, severe rigidity and autonomic instability
Q41. Which clinical parameter is especially important to check before starting risperidone in patients with diabetes?
- Baseline fasting blood glucose and HbA1c
- Serum bilirubin only
- Urine culture
- Serum potassium only
Correct Answer: Baseline fasting blood glucose and HbA1c
Q42. Which symptom suggests hyperprolactinemia induced by risperidone?
- Excessive sweating only
- Galactorrhea, amenorrhea, or sexual dysfunction
- Easy bruising
- Peripheral neuropathy
Correct Answer: Galactorrhea, amenorrhea, or sexual dysfunction
Q43. Which formulation change is used in Risperdal Consta to provide long-acting release?
- Immediate-release syrup
- Polymeric microsphere intramuscular injection
- Transdermal patch with continuous infusion
- Oral gastroretentive tablet
Correct Answer: Polymeric microsphere intramuscular injection
Q44. Which is a recommended approach for managing antipsychotic-induced akathisia?
- Increasing the risperidone dose
- Adding a beta-blocker or benzodiazepine
- Immediate initiation of clozapine
- Ignoring symptoms as they resolve without treatment
Correct Answer: Adding a beta-blocker or benzodiazepine
Q45. Which receptor profile difference largely accounts for lower extrapyramidal side effects of many atypical antipsychotics?
- Higher muscarinic receptor blockade
- Higher 5-HT2A relative to D2 antagonism
- Exclusive opioid receptor antagonism
- Greater beta-adrenergic blockade
Correct Answer: Higher 5-HT2A relative to D2 antagonism
Q46. Which of the following is TRUE regarding risperidone’s effect on lipid profiles?
- Risperidone consistently lowers triglycerides
- Risperidone can cause increases in triglycerides and cholesterol
- Risperidone has no effect on metabolic parameters
- It only affects HDL and no other lipid fractions
Correct Answer: Risperidone can cause increases in triglycerides and cholesterol
Q47. Which adverse effect is LEAST likely with risperidone compared to many other atypicals?
- Severe neutropenia and agranulocytosis
- Weight gain
- Hyperprolactinemia
- Orthostatic hypotension
Correct Answer: Severe neutropenia and agranulocytosis
Q48. Which monitoring schedule is appropriate after initiating risperidone in an adult patient?
- No monitoring is ever required
- Baseline and periodic metabolic (weight, glucose, lipids) and EPS assessment
- Daily EEG monitoring
- Weekly bone marrow biopsy
Correct Answer: Baseline and periodic metabolic (weight, glucose, lipids) and EPS assessment
Q49. Which pharmacokinetic feature explains why some patients have variable responses to risperidone?
- Uniform metabolism independent of genetics
- Polymorphic CYP2D6 activity leading to variable clearance
- Absence of hepatic metabolism
- Exclusive elimination via bile without variability
Correct Answer: Polymorphic CYP2D6 activity leading to variable clearance
Q50. Which clinical action is recommended if a patient on risperidone develops significant hyperprolactinemia with symptomatic effects?
- Continue the same dose without assessment
- Evaluate for symptoms, consider dose reduction, switch to less prolactin-elevating agent
- Add a dopamine antagonist to increase prolactin further
- Stop all antipsychotic treatment immediately without alternative
Correct Answer: Evaluate for symptoms, consider dose reduction, switch to less prolactin-elevating agent

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.
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