Medicinal uses of quinoline MCQs With Answer

Medicinal uses of quinoline MCQs With Answer are essential for B. Pharm students studying antimalarial and broad-spectrum therapeutic agents. This focused introduction reviews core concepts—quinoline scaffold, key derivatives (quinine, chloroquine, primaquine, mefloquine), mechanisms like inhibition of heme detoxification, structure–activity relationships, resistance mechanisms (PfCRT, PfMDR1), pharmacokinetics, metabolism, adverse effects (retinopathy, hemolysis in G6PD deficiency), and clinical indications beyond malaria such as antibacterial and anticancer research. These MCQs with answers are designed to reinforce understanding, improve exam readiness, and deepen practical knowledge of drug design, safety monitoring, and lab assays related to quinoline drugs. Now let’s test your knowledge with 50 MCQs on this topic.

Q1. Which structural feature is central to the quinoline pharmacophore?

• Fused benzene and pyridine ring
• Spirocyclic lactone ring
• Beta-lactam ring
• Indole core

Correct Answer: Fused benzene and pyridine ring

Q2. Which quinoline derivative is a classic blood schizonticide widely used for malaria treatment?

• Primaquine
• Chloroquine
• Atovaquone
• Tetracycline

Correct Answer: Chloroquine

Q3. What is the primary mechanism by which 4-aminoquinolines (e.g., chloroquine) act against Plasmodium?

• Inhibition of folate synthesis
• Blocking heme detoxification (hemozoin formation)
• Inhibiting cell wall synthesis
• Activating host immune cells

Correct Answer: Blocking heme detoxification (hemozoin formation)

Q4. Which quinoline derivative is particularly active against hypnozoites of Plasmodium vivax?

• Mefloquine
• Primaquine
• Quinine
• Chloroquine

Correct Answer: Primaquine

Q5. Cinchonism is an adverse effect classically associated with which quinoline alkaloid?

• Chloroquine
• Quinine
• Primaquine
• Mefloquine

Correct Answer: Quinine

Q6. Which enzyme family is primarily responsible for hepatic metabolism of many quinoline drugs?

• CYP450 (cytochrome P450)
• MAO (monoamine oxidase)
• Acetylcholinesterase
• Glutathione-S-transferase only

Correct Answer: CYP450 (cytochrome P450)

Q7. Resistance to chloroquine in Plasmodium falciparum is commonly linked to mutations in which transporter?

• P-glycoprotein
• PfCRT (chloroquine resistance transporter)
• H+-ATPase
• Na+/K+ pump

Correct Answer: PfCRT (chloroquine resistance transporter)

Q8. Which quinoline class is most associated with dose-dependent retinal toxicity?

• 8-aminoquinolines
• 4-aminoquinolines
• Quinazoline derivatives
• Isoquinolines

Correct Answer: 4-aminoquinolines

Q9. Which synthetic route is a classical method for preparing the quinoline core in medicinal chemistry?

• Friedel–Crafts acylation
• Skraup synthesis
• Bischler–Möhlau reaction
• Wittig reaction

Correct Answer: Skraup synthesis

Q10. Which side effect is a major contraindication for prescribing primaquine without testing?

• Renal insufficiency
• G6PD deficiency leading to hemolytic anemia
• Hypothyroidism
• Hyperkalemia

Correct Answer: G6PD deficiency leading to hemolytic anemia

Q11. Mefloquine is best described as which type of quinoline derivative?

• 4-aminoquinoline
• 8-aminoquinoline
• Methanol quinoline
• Quinazoline analog

Correct Answer: 4-aminoquinoline

Q12. Which analytical technique is commonly used to quantify quinoline drugs in plasma for pharmacokinetic studies?

• Thin-layer chromatography only
• High-performance liquid chromatography (HPLC)
• Gram staining
• Flame photometry

Correct Answer: High-performance liquid chromatography (HPLC)

Q13. Which pharmacokinetic property explains chloroquine’s prolonged terminal half-life?

• High renal clearance
• Large volume of distribution and tissue binding
• Low protein binding
• Rapid first-pass metabolism

Correct Answer: Large volume of distribution and tissue binding

Q14. Which modification generally increases antimalarial activity in quinoline SAR studies?

• Adding bulky polar groups at the 2-position
• Introducing a basic side chain at the 4-position
• Removal of aromaticity
• Converting to a saturated cyclohexane

Correct Answer: Introducing a basic side chain at the 4-position

Q15. Which quinoline derivative is known for neuropsychiatric adverse effects including vivid dreams?

• Mefloquine
• Primaquine
• Chloroquine
• Quinidine

Correct Answer: Mefloquine

Q16. Quinoline antimalarials interfere with parasite growth primarily in which parasite compartment?

• Parasitophorous vacuole membrane only
• Food vacuole (digestive vacuole)
• Mitochondrial matrix exclusively
• Apicoplast DNA

Correct Answer: Food vacuole (digestive vacuole)

Q17. Which quinoline drug is sometimes used intravenously for severe malaria?

• Chloroquine phosphate IV (commonly used historically)
• Primaquine IV
• Mefloquine IV
• Artemisinin derivatives are preferred; quinine IV historically

Correct Answer: Artemisinin derivatives are preferred; quinine IV historically

Q18. What laboratory test is critical before prescribing primaquine to prevent hemolysis?

• Serum creatinine
• G6PD assay
• Chest X-ray
• ECG

Correct Answer: G6PD assay

Q19. Which adverse effect is associated with high cumulative doses of chloroquine?

• Hepatic fibrosis
• Retinopathy and visual field defects
• Ototoxicity only
• Hyperglycemia

Correct Answer: Retinopathy and visual field defects

Q20. Which property of quinoline drugs contributes to accumulation in acidic parasite compartments?

• High lipophilicity and weakly basic nature (pKa-dependent ion trapping)
• Strong acidic character
• Neutral hydrophilicity
• Permanent positive charge

Correct Answer: High lipophilicity and weakly basic nature (pKa-dependent ion trapping)

Q21. Which derivative is primarily used as an anti-arrhythmic rather than antimalarial?

• Quinidine
• Chloroquine
• Mefloquine
• Primaquine

Correct Answer: Quinidine

Q22. Which molecular target is inhibited by some quinoline-based anticancer agents?

• Topoisomerase enzymes
• Insulin receptor
• Hemoglobin synthesis enzymes only
• Peptidoglycan transpeptidase

Correct Answer: Topoisomerase enzymes

Q23. Which metabolic pathway is most involved in dealkylation of chloroquine?

• Phase II glucuronidation only
• Cytochrome P450-mediated N-dealkylation
• Lipoxygenase pathway
• Beta-oxidation

Correct Answer: Cytochrome P450-mediated N-dealkylation

Q24. Which assay would be used to measure antimalarial activity of new quinoline derivatives in vitro?

• MIC assay for bacteria
• Parasite growth inhibition assay (e.g., P. falciparum culture IC50)
• ELISA for cytokines only
• Serum creatinine assay

Correct Answer: Parasite growth inhibition assay (e.g., P. falciparum culture IC50)

Q25. Which interaction is important to consider with chloroquine and other QT-prolonging drugs?

• Enhanced anticoagulation only
• Risk of additive QT prolongation and torsades de pointes
• Reduced efficacy of both drugs without cardiac risk
• Increased renal clearance of chloroquine

Correct Answer: Risk of additive QT prolongation and torsades de pointes

Q26. Which property of quinoline-based antimalarials allows once-weekly dosing for prophylaxis (e.g., mefloquine)?

• Extremely low oral bioavailability
• Long elimination half-life and tissue retention
• Rapid renal elimination
• Requirement for frequent dosing due to short half-life

Correct Answer: Long elimination half-life and tissue retention

Q27. Which quinoline derivative can cause hemolysis in G6PD-deficient patients besides primaquine?

• Chloroquine
• Quinine (in some cases)**
• Atovaquone
• Doxycycline

Correct Answer: Quinine (in some cases)**

Q28. Which diagnostic monitoring is recommended during long-term therapy with 4-aminoquinolines?

• Periodic ophthalmologic (retinal) exams
• Daily liver biopsies
• Monthly MRI scans
• No monitoring is needed

Correct Answer: Periodic ophthalmologic (retinal) exams

Q29. In drug design, adding electron-donating groups to the quinoline ring generally affects which property?

• Decreases pKa dramatically making drug more acidic
• Modifies electronic distribution, potentially altering potency and metabolism
• Makes the compound completely inactive biologically
• Destroys the aromaticity making synthesis impossible

Correct Answer: Modifies electronic distribution, potentially altering potency and metabolism

Q30. Which quinoline is known for use in babesiosis and sometimes combined with azithromycin?

• Chloroquine
• Quinine
• Atovaquone is preferred; quinoline role is limited
• Primaquine

Correct Answer: Atovaquone is preferred; quinoline role is limited

Q31. Which resistance mechanism involves reduced drug accumulation in the parasite’s digestive vacuole?

• Increased drug metabolism by human liver
• Mutations in PfCRT leading to efflux or reduced uptake
• Host antibody neutralization
• Increased blood–brain barrier transport

Correct Answer: Mutations in PfCRT leading to efflux or reduced uptake

Q32. Which formulation concern is important for oral quinoline tablets to improve bioavailability?

• Use of enteric coating to avoid stomach absorption only
• Optimizing solubility and dissolution rate
• Always making them injectable instead
• Avoiding any excipients to keep drug pure

Correct Answer: Optimizing solubility and dissolution rate

Q33. Which laboratory parameter should be monitored when using quinidine (a quinoline derivative) clinically?

• Serum potassium and ECG monitoring for arrhythmias
• Serum amylase only
• Urine glucose daily
• Platelet count only

Correct Answer: Serum potassium and ECG monitoring for arrhythmias

Q34. Which quinoline modification is associated with increased activity against chloroquine-resistant strains?

• Shortening side chain to reduce basicity
• Designing hybrid molecules or adding bulky side chains to evade resistance transporters
• Removing all nitrogen atoms
• Converting to a peptide

Correct Answer: Designing hybrid molecules or adding bulky side chains to evade resistance transporters

Q35. Which adverse effect is commonly associated with chloroquine overdose?

• Hypoglycemia, cardiac arrhythmias, and CNS depression
• Hyperactivity and insomnia only
• Excessive hair growth
• Immediate renal failure only

Correct Answer: Hypoglycemia, cardiac arrhythmias, and CNS depression

Q36. Which cell organelle in Plasmodium is targeted indirectly by some quinoline hybrids causing mitochondrial dysfunction?

• Nucleus exclusively
• Mitochondrion
• Ribosome only
• Golgi apparatus only

Correct Answer: Mitochondrion

Q37. Which route of elimination is most significant for many quinoline drugs?

• Primarily biliary and hepatic metabolism with renal excretion of metabolites
• Exclusive exhalation through lungs
• Complete unchanged renal excretion
• Sequestration in bone permanently

Correct Answer: Primarily biliary and hepatic metabolism with renal excretion of metabolites

Q38. Which clinical use beyond malaria has quinoline scaffolds been explored for?

• Antidepressant therapy only
• Antibacterial, antiviral, and anticancer agents
• Replacement for insulin
• Exclusive use as topical anesthetics

Correct Answer: Antibacterial, antiviral, and anticancer agents

Q39. Which monitoring is recommended when prescribing chloroquine with other hepatically metabolized drugs?

• No monitoring required ever
• Monitor for drug–drug interactions and liver enzyme alterations
• Only monitor blood pressure
• Only monitor pulmonary function

Correct Answer: Monitor for drug–drug interactions and liver enzyme alterations

Q40. Which chemical property is key to quinoline drugs accumulating in acidic compartments?

• Strong acidity (pKa < 2)
• Weakly basic amine functionality with appropriate pKa
• Permanent zwitterionic nature
• Neutral glycosidic bonds

Correct Answer: Weakly basic amine functionality with appropriate pKa

Q41. Which quinoline drug has been associated with severe cardiac toxicity in overdose and requires ECG monitoring?

• Primaquine
• Quinine/Quinidine
• Amoxicillin
• Furosemide

Correct Answer: Quinine/Quinidine

Q42. Which lab technique is suitable for structural elucidation of novel quinoline derivatives?

• NMR spectroscopy and mass spectrometry
• Gram staining only
• Visual inspection only
• Simple pH test only

Correct Answer: NMR spectroscopy and mass spectrometry

Q43. Which factor often reduces clinical efficacy of chloroquine in many endemic regions?

• Lack of drug stability in tablets only
• Widespread parasite resistance due to genetic mutations
• Lack of patient adherence only
• Excessive protein binding only

Correct Answer: Widespread parasite resistance due to genetic mutations

Q44. Which toxic effect requires immediate cessation of chloroquine therapy?

• Transient mild nausea
• Signs of visual impairment or retinopathy
• Slight headache for an hour
• Mild thirst

Correct Answer: Signs of visual impairment or retinopathy

Q45. Which property is crucial when designing quinoline derivatives to cross the parasite membranes?

• Excessive hydrophilicity only
• Balanced lipophilicity and ionization state (pKa)
• Extremely large molecular weight (>1000 Da)
• Complete ionic permanent charge

Correct Answer: Balanced lipophilicity and ionization state (pKa)

Q46. Which therapeutic application has 8-aminoquinolines been especially developed for?

• Treatment of bacterial infections only
• Radical cure of relapsing malaria by targeting liver hypnozoites
• Local anesthetic in dentistry
• Replacement for statins

Correct Answer: Radical cure of relapsing malaria by targeting liver hypnozoites

Q47. Which animal toxicity model is commonly used in preclinical safety assessment of quinoline analogs?

• Neurobehavioral and cardiac toxicity studies in rodents
• Only in silico prediction without animals
• Plant toxicity assays only
• Fish embryo toxicity only

Correct Answer: Neurobehavioral and cardiac toxicity studies in rodents

Q48. Which formulation strategy can reduce gastrointestinal irritation of quinoline tablets?

• Use of immediate-release high-dose tablets only
• Enteric coating or incorporation of buffering excipients
• Avoiding any excipient entirely
• Making them into bitter syrups only

Correct Answer: Enteric coating or incorporation of buffering excipients

Q49. Which laboratory parameter may be altered by severe quinine toxicity requiring monitoring?

• Serum glucose only
• Electrolytes and ECG for arrhythmias
• Urine pH only
• Serum vitamin D only

Correct Answer: Electrolytes and ECG for arrhythmias

Q50. Which research approach helps overcome quinoline resistance in modern drug development?

• Ignoring resistance and using higher doses
• Designing hybrid molecules, combination therapy, and targeting novel parasite pathways
• Using quinolines only as monotherapy forever
• Abandoning molecular design entirely

Correct Answer: Designing hybrid molecules, combination therapy, and targeting novel parasite pathways

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.

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