Niclosamide, Oxamniquine, Praziquantel, Ivermectin MCQs With Answer

Niclosamide, Oxamniquine, Praziquantel, Ivermectin MCQs With Answer
This concise guide introduces four important anthelmintics—Niclosamide, Oxamniquine, Praziquantel and Ivermectin—for B.Pharm students. It covers spectrum of activity (cestodes, trematodes, nematodes), mechanisms of action (mitochondrial uncoupling, tegument disruption, Ca2+ influx, glutamate‑gated chloride channel modulation), pharmacokinetics, clinical uses, adverse effects and key drug interactions. Emphasis is on features relevant to formulation, dosing rationale, safety in pregnancy, and resistance issues. Questions are designed to reinforce clinical pharmacology, medicinal chemistry and therapeutics. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. Which drug is the drug of choice for most intestinal tapeworm (cestode) infections due to its minimal systemic absorption?

• Praziquantel
• Oxamniquine
• Niclosamide
• Ivermectin

Correct Answer: Niclosamide

Q2. The primary mechanism of action of praziquantel against schistosomes is:

• Inhibition of mitochondrial ATP synthase
• Increased membrane permeability to calcium leading to tetanic paralysis
• Competitive antagonism of nicotinic acetylcholine receptors
• Activation of glutamate-gated chloride channels

Correct Answer: Increased membrane permeability to calcium leading to tetanic paralysis

Q3. Ivermectin exerts its antiparasitic effects mainly by binding to which target in invertebrates?

• Voltage-gated sodium channels
• Glutamate-gated chloride channels
• Nicotinic acetylcholine receptors
• GABA-B receptors

Correct Answer: Glutamate-gated chloride channels

Q4. Oxamniquine is primarily used in infections caused by which parasite?

• Taenia solium
• Schistosoma mansoni
• Onchocerca volvulus
• Enterobius vermicularis

Correct Answer: Schistosoma mansoni

Q5. A key pharmacokinetic property of niclosamide that determines its use is:

• Extensive hepatic metabolism with active metabolites
• High oral bioavailability and systemic distribution
• Negligible systemic absorption, acting locally in the gut lumen
• Renal excretion as unchanged drug requiring dose adjustment in renal impairment

Correct Answer: Negligible systemic absorption, acting locally in the gut lumen

Q6. Which adverse effect is most commonly associated with praziquantel therapy?

• Severe neutropenia
• Transient dizziness, headache and abdominal discomfort
• Ototoxicity with tinnitus
• Fixed drug eruption

Correct Answer: Transient dizziness, headache and abdominal discomfort

Q7. Which drug should be used with caution or pre-treatment steroids in neurocysticercosis to reduce inflammatory reactions?

• Niclosamide
• Oxamniquine
• Praziquantel
• Ivermectin

Correct Answer: Praziquantel

Q8. The likely reason ivermectin is ineffective against adult tapeworms is:

• Tapeworms lack glutamate-gated chloride channels targeted by ivermectin
• Ivermectin does not reach the biliary tree where tapeworms reside
• Ivermectin is rapidly degraded by tapeworm enzymes
• Ivermectin is highly protein bound and cannot bind parasites

Correct Answer: Tapeworms lack glutamate-gated chloride channels targeted by ivermectin

Q9. Niclosamide’s antiparasitic action is primarily by:

• DNA intercalation preventing replication
• Uncoupling oxidative phosphorylation in parasite mitochondria
• Increasing membrane sodium permeability
• Inhibition of microtubule polymerization

Correct Answer: Uncoupling oxidative phosphorylation in parasite mitochondria

Q10. Oxamniquine’s major clinical effect on schistosomes includes:

• Interference with worm glucose uptake only
• Induction of muscular paralysis and separation from mesenteric veins
• Inhibition of tegumental calcium channels
• Disruption of microtubules leading to decreased egg laying

Correct Answer: Induction of muscular paralysis and separation from mesenteric veins

Q11. Which of the following drugs is most appropriate for treating onchocerciasis (river blindness)?

• Ivermectin
• Niclosamide
• Praziquantel
• Oxamniquine

Correct Answer: Ivermectin

Q12. Which statement about praziquantel pharmacokinetics is correct?

• It is poorly absorbed and acts only in the gut lumen
• It is rapidly absorbed and extensively metabolized in the liver
• It is excreted unchanged in bile with minimal metabolism
• It requires renal dosing adjustments in mild renal impairment

Correct Answer: It is rapidly absorbed and extensively metabolized in the liver

Q13. A major contraindication or precaution for ivermectin use is:

• Use in infants and young children under recommended weight limits
• Use in patients with hepatic steatosis due to severe hepatotoxicity
• Use in intestinal tapeworm infections due to severe anaphylaxis
• Use with antacids because of reduced absorption

Correct Answer: Use in infants and young children under recommended weight limits

Q14. Which drug is administered orally and acts mainly on luminal cestodes without systemic effects?

• Oxamniquine
• Praziquantel
• Niclosamide
• Ivermectin

Correct Answer: Niclosamide

Q15. The Mazzotti-type reaction (fever, pruritus, lymphadenopathy) after antiparasitic therapy is most associated with treatment of:

• Neurocysticercosis with niclosamide
• Onchocerciasis with ivermectin
• Cestode infections with praziquantel
• Schistosomiasis with oxamniquine

Correct Answer: Onchocerciasis with ivermectin

Q16. Which drug requires conversion to an active metabolite within the parasite for full activity against schistosomes?

• Ivermectin
• Oxamniquine
• Niclosamide
• Praziquantel

Correct Answer: Oxamniquine

Q17. Drug interactions: co-administration of strong CYP3A4 inhibitors may increase plasma levels of which drug, requiring caution?

• Niclosamide
• Oxamniquine
• Praziquantel
• None of the above

Correct Answer: Praziquantel

Q18. Which antiparasitic is most appropriate for treating intestinal strongyloidiasis?

• Niclosamide
• Ivermectin
• Praziquantel
• Oxamniquine

Correct Answer: Ivermectin

Q19. A pharmacological advantage of praziquantel in schistosomiasis control programs is:

• Single-dose efficacy against many trematodes and cestodes
• Complete lack of adverse reactions in heavy infections
• Exclusive luminal action avoiding systemic effects
• Resistance is non-existent worldwide

Correct Answer: Single-dose efficacy against many trematodes and cestodes

Q20. Which drug is least likely to be effective for tissue-dwelling cystic lesions because it is not systemically absorbed?

• Niclosamide
• Praziquantel
• Ivermectin
• Oxamniquine

Correct Answer: Niclosamide

Q21. Which side effect is particularly associated with oxamniquine therapy?

• Hepatotoxicity and dizziness
• CNS depression and hallucinations
• Severe cardiotoxicity
• Renal tubular necrosis

Correct Answer: Hepatotoxicity and dizziness

Q22. Resistance to ivermectin in parasitic nematodes is mainly linked to:

• Mutations in glutamate-gated chloride channel genes
• Upregulation of mitochondrial uncoupling proteins
• Increased tegument repair mechanisms
• Enhanced drug efflux by P-glycoprotein in humans

Correct Answer: Mutations in glutamate-gated chloride channel genes

Q23. In which situation is praziquantel therapy likely to produce the most pronounced adverse inflammatory reaction?

• Intestinal tapeworm carriage without tissue invasion
• Ocular cysticercosis without steroid cover
• Uncomplicated urinary schistosomiasis
• Cutaneous larva migrans

Correct Answer: Ocular cysticercosis without steroid cover

Q24. Which statement about niclosamide formulation is correct?

• It is given parenterally for systemic cestode infections
• It is administered orally, often as a chewable tablet, for luminal tapeworms
• It requires co-administration with high-fat meal to enhance absorption
• It is primarily used topically for cutaneous helminth infections

Correct Answer: It is administered orally, often as a chewable tablet, for luminal tapeworms

Q25. Which drug’s major therapeutic use includes mass drug administration programs for lymphatic filariasis and onchocerciasis?

• Niclosamide
• Oxamniquine
• Ivermectin
• Praziquantel

Correct Answer: Ivermectin

Q26. A pharmacodynamic effect of praziquantel on parasites includes all EXCEPT:

• Disruption of tegument leading to exposure of antigens
• Enhanced susceptibility to host immune mechanisms
• Direct inhibition of parasite glycolytic enzymes causing immediate death
• Spastic paralysis due to increased intracellular calcium

Correct Answer: Direct inhibition of parasite glycolytic enzymes causing immediate death

Q27. When advising on safety, which drug has documented teratogenic risk in animal studies and is generally avoided in pregnancy unless benefit outweighs risk?

• Ivermectin
• Niclosamide
• Oxamniquine
• Praziquantel

Correct Answer: Ivermectin

Q28. Which laboratory monitoring is most relevant after treating heavy schistosomal infections with praziquantel?

• Serial liver function tests due to possible hepatic inflammation
• Frequent ECG monitoring for QT prolongation
• Daily complete blood count for agranulocytosis
• Serum creatinine for rapid renal failure

Correct Answer: Serial liver function tests due to possible hepatic inflammation

Q29. Which of the following best describes oxamniquine’s spectrum of activity?

• Broad-spectrum nematocide effective against Strongyloides and Ascaris
• Primarily active against Schistosoma mansoni with limited other uses
• First-line agent for Taenia saginata and Taenia solium intestinal infections
• Effective for onchocerciasis and cutaneous larva migrans

Correct Answer: Primarily active against Schistosoma mansoni with limited other uses

Q30. Which pharmacological principle explains why niclosamide remains effective despite minimal systemic absorption?

• High therapeutic index due to selective uptake by parasite mitochondria in the lumen
• Host immune activation requiring systemic distribution
• Ability to cross the blood-brain barrier and act on cerebral parasites
• Renal accumulation providing prolonged exposure

Correct Answer: High therapeutic index due to selective uptake by parasite mitochondria in the lumen

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