Antimalarial drugs are an important topic in pharmacology for B.Pharm, D.Pharm, GPAT, Drug Inspector and pharmacist recruitment examinations. Questions commonly cover the classification of antimalarial drugs, mechanisms of action, therapeutic uses, adverse effects and the life cycle of Plasmodium.
In this article, you will find 30 important multiple-choice questions (MCQs) on antimalarial drugs, along with correct answers and explanations to help you revise the topic.
📝Antimalarial Drugs MCQs
1. Malaria is caused by which type of organism?
A. Bacteria
B. Virus
C. Protozoan parasite
D. Fungus
Correct Answer: C. Protozoan parasite
Explanation: Malaria is caused by protozoan parasites belonging to the genus Plasmodium. Infection is usually transmitted through the bite of an infected female Anopheles mosquito.
2. Which mosquito transmits malaria to humans?
A. Aedes
B. Culex
C. Female Anopheles
D. Male Anopheles
Correct Answer: C. Female Anopheles
Explanation: The infected female Anopheles mosquito transmits malaria parasites during a blood meal.
3. Which of the following is an artemisinin derivative?
A. Artesunate
B. Primaquine
C. Chloroquine
D. Proguanil
Correct Answer: A. Artesunate
Explanation: Artesunate is a rapidly acting artemisinin derivative used in recommended malaria treatment regimens.
4. Chloroquine primarily interferes with which process in susceptible malaria parasites?
A. Bacterial cell-wall synthesis
B. Haem detoxification
C. Human DNA synthesis
D. Fungal ergosterol synthesis
Correct Answer: B. Haem detoxification
Explanation: Chloroquine interferes with the detoxification of haem inside the parasite’s food vacuole, allowing toxic haem-related products to accumulate.
5. Which drug is particularly important for preventing relapse in Plasmodium vivax malaria?
A. Primaquine
B. Amoxicillin
C. Fluconazole
D. Metronidazole
Correct Answer: A. Primaquine
Explanation: Primaquine can eliminate dormant liver forms called hypnozoites in eligible patients, helping prevent relapse. G6PD testing is necessary before treatment because of the risk of haemolysis.
6. Which parasite stage is responsible for relapse in P. vivax and P. ovale malaria?
A. Merozoite
B. Hypnozoite
C. Gametocyte only
D. Sporozoite in the mosquito
Correct Answer: B. Hypnozoite
Explanation: Hypnozoites can remain dormant in the liver and reactivate later, producing recurrent infections.
7. Which enzyme is inhibited by pyrimethamine?
A. Dihydrofolate reductase
B. Cyclooxygenase
C. Acetylcholinesterase
D. DNA gyrase
Correct Answer: A. Dihydrofolate reductase
Explanation: Pyrimethamine inhibits parasite dihydrofolate reductase, interfering with folate metabolism and nucleic-acid synthesis.
8. Proguanil is converted in the body to which active metabolite?
A. Cycloguanil
B. Acetylsalicylic acid
C. Norfloxacin
D. Sulfanilamide
Correct Answer: A. Cycloguanil
Explanation: Cycloguanil inhibits parasite dihydrofolate reductase and contributes to proguanil’s antimalarial activity.
9. Atovaquone acts primarily by inhibiting which target?
A. Parasite mitochondrial electron transport
B. Bacterial ribosomes
C. Human histamine receptors
D. Fungal cell-wall synthesis
Correct Answer: A. Parasite mitochondrial electron transport
Explanation: Atovaquone interferes with the parasite’s mitochondrial electron transport chain and is used in combination with proguanil for selected indications.
10. Which adverse effect is particularly associated with quinine?
A. Cinchonism
B. Tendon rupture in every patient
C. Permanent hair growth
D. Severe constipation in every patient
Correct Answer: A. Cinchonism
Explanation: Cinchonism may include tinnitus, headache, dizziness, nausea and visual disturbances.
11. Which antimalarial drug can cause haemolytic anaemia in patients with G6PD deficiency?
A. Primaquine
B. Paracetamol
C. Omeprazole
D. Cetirizine
Correct Answer: A. Primaquine
Explanation: Primaquine can cause clinically significant haemolysis in people with glucose-6-phosphate dehydrogenase deficiency. G6PD status must be assessed before use.
12. Which of the following is an 8-aminoquinoline?
A. Primaquine
B. Chloroquine
C. Quinine
D. Lumefantrine
Correct Answer: A. Primaquine
Explanation: Primaquine belongs to the 8-aminoquinoline class and is used for selected liver-stage and transmission-related indications.
13. Artemisinin-based combination therapy is commonly abbreviated as:
A. ACT
B. NSAID
C. PPI
D. ACEI
Correct Answer: A. ACT
Explanation: ACT stands for artemisinin-based combination therapy. It combines an artemisinin derivative with a partner antimalarial drug.
14. Why are artemisinin derivatives commonly used in combination therapy?
A. To eliminate the need for diagnosis
B. To combine rapid parasite reduction with an effective partner drug
C. To treat bacterial pneumonia
D. To prevent all drug adverse effects
Correct Answer: B. To combine rapid parasite reduction with an effective partner drug
Explanation: Artemisinin derivatives reduce parasite numbers rapidly, while the partner drug contributes to clearing the infection. Recommended combinations also help limit resistance development.
15. Which drug combination is used for selected malaria treatment and prevention indications?
A. Atovaquone and proguanil
B. Omeprazole and pantoprazole
C. Amoxicillin and clavulanate
D. Levodopa and carbidopa
Correct Answer: A. Atovaquone and proguanil
Explanation: Atovaquone-proguanil is a recognised antimalarial combination. Its suitability depends on the indication and patient-specific factors.
16. Which of the following is an artemisinin derivative?
A. Artemether
B. Pyrimethamine
C. Doxycycline
D. Mefloquine
Correct Answer: A. Artemether
Explanation: Artemether is an artemisinin derivative used in combination regimens, including artemether-lumefantrine.
17. Which drug may be used in combination with an antimalarial for selected treatment or prevention regimens?
A. Doxycycline
B. Fluconazole
C. Acyclovir
D. Pantoprazole
Correct Answer: A. Doxycycline
Explanation: Doxycycline has activity against malaria parasites and is used in selected treatment combinations and prevention regimens. Its use depends on the indication and patient factors.
18. Which of the following is a recognised antimalarial drug?
A. Mefloquine
B. Metformin
C. Furosemide
D. Loratadine
Correct Answer: A. Mefloquine
Explanation: Mefloquine is an antimalarial medicine used for selected treatment and prevention indications. It can cause important neuropsychiatric adverse effects.
19. Which adverse effect is an important concern with mefloquine?
A. Neuropsychiatric reactions
B. Tooth decay in every patient
C. Increased insulin production in every patient
D. Complete loss of hearing in every patient
Correct Answer: A. Neuropsychiatric reactions
Explanation: Mefloquine can cause neuropsychiatric adverse effects, including abnormal dreams, anxiety and, in some cases, serious psychiatric or neurological symptoms.
20. Which of the following is a blood-stage antimalarial drug used only where parasites remain susceptible?
A. Chloroquine
B. Primaquine alone for every malaria infection
C. Fluconazole
D. Acyclovir
Correct Answer: A. Chloroquine
Explanation: Chloroquine treats susceptible blood-stage malaria parasites. Resistance limits its use in many locations, so treatment choice must follow local guidance.
21. Which antimalarial drug is commonly associated with retinal toxicity after prolonged or inappropriate exposure?
A. Chloroquine
B. Artesunate
C. Proguanil
D. Clindamycin
Correct Answer: A. Chloroquine
Explanation: Retinal toxicity is an important safety concern with chloroquine, particularly with prolonged exposure or inappropriate dosing.
22. Which medicine is used for the initial treatment of severe malaria in many current guidelines?
A. Intravenous artesunate
B. Oral primaquine alone
C. Oral doxycycline alone
D. Oral chloroquine in every case
Correct Answer: A. Intravenous artesunate
Explanation: Severe malaria is a medical emergency. Intravenous artesunate is recommended in many current guidelines, followed by a complete oral treatment regimen when appropriate.
23. What is the main purpose of using antimalarial medicines?
A. To eliminate malaria parasites
B. To treat every viral infection
C. To prevent all bacterial infections
D. To increase blood glucose
Correct Answer: A. To eliminate malaria parasites
Explanation: Antimalarial medicines target the parasite and help cure infection, prevent complications and reduce transmission.
24. Which of the following is a malaria parasite species?
A. Plasmodium falciparum
B. Escherichia coli
C. Candida albicans
D. Staphylococcus aureus
Correct Answer: A. Plasmodium falciparum
Explanation: P. falciparum is a malaria parasite associated with severe disease and potentially life-threatening complications.
25. Which parasite species can cause relapsing malaria due to dormant liver forms?
A. P. vivax and P. ovale
B. P. malariae only
C. P. falciparum only
D. All bacterial pathogens
Correct Answer: A. P. vivax and P. ovale
Explanation: These species can form dormant liver hypnozoites that reactivate later and cause relapse.
26. Which statement about antimalarial drug resistance is correct?
A. Resistance can affect the choice of treatment
B. Resistance never occurs
C. All antimalarial drugs work equally in every region
D. Resistance only affects antibiotics
Correct Answer: A. Resistance can affect the choice of treatment
Explanation: Resistance patterns vary geographically and may reduce the effectiveness of particular medicines. Treatment recommendations are updated as resistance changes.
27. Why should suspected malaria be confirmed with an appropriate diagnostic test when available?
A. Symptoms alone cannot reliably distinguish malaria from other causes of fever
B. Testing is never useful
C. Every fever is malaria
D. Antimalarial drugs treat every infection
Correct Answer: A. Symptoms alone cannot reliably distinguish malaria from other causes of fever
Explanation: Malaria symptoms overlap with many other illnesses. Microscopy or a rapid diagnostic test helps confirm infection and supports appropriate treatment.
28. Which drug combination contains an artemisinin derivative and a partner antimalarial?
A. Artemether-lumefantrine
B. Atovaquone-proguanil
C. Omeprazole-amoxicillin
D. Sulfamethoxazole-trimethoprim
Correct Answer: A. Artemether-lumefantrine
Explanation: Artemether-lumefantrine is an ACT used for appropriate malaria indications according to current local guidelines.
29. Which statement about primaquine and tafenoquine is correct?
A. G6PD assessment is important before use
B. They are antifungal medicines
C. They are used to treat hypertension
D. They are suitable for everyone without assessment
Correct Answer: A. G6PD assessment is important before use
Explanation: Both medicines can cause haemolysis in people with G6PD deficiency. Patient eligibility and other precautions must be assessed before treatment.
30. Which is the most appropriate approach to malaria treatment?
A. Take leftover medicines without testing
B. Choose medicines solely based on fever symptoms
C. Follow a confirmed diagnosis and current treatment guidance
D. Stop treatment as soon as fever decreases
Correct Answer: C. Follow a confirmed diagnosis and current treatment guidance
Explanation: Effective treatment depends on parasite species, disease severity, resistance patterns and patient-specific factors. The prescribed course should be completed as directed.
📑Quick Revision: Antimalarial Drugs
- Chloroquine: Interferes with haem detoxification in susceptible parasites.
- Artesunate: Rapidly acting artemisinin derivative.
- Primaquine: Used for selected liver-stage treatment and relapse prevention.
- Pyrimethamine: Inhibits parasite dihydrofolate reductase.
- Proguanil: Converted to cycloguanil, which inhibits parasite dihydrofolate reductase.
- Atovaquone: Inhibits parasite mitochondrial electron transport.
- Quinine: Associated with cinchonism.
- Mefloquine: Important concern is neuropsychiatric adverse effects.
- ACT: Artemisinin-based combination therapy.
- Severe malaria: Requires urgent medical treatment.
📋Frequently Asked Questions
1. Which antimalarial drugs are important for GPAT?
Important examples include chloroquine, primaquine, quinine, artesunate, artemether, pyrimethamine, proguanil, atovaquone and mefloquine.
2. What is the mechanism of action of chloroquine?
Chloroquine interferes with haem detoxification in the parasite’s food vacuole.
3. Why is primaquine important?
Primaquine can eliminate dormant liver-stage parasites in eligible patients with P. vivax or P. ovale infection, helping prevent relapse.
4. Why is G6PD testing needed before primaquine treatment?
Primaquine can cause haemolytic anaemia in people with G6PD deficiency.
5. What does ACT stand for?
ACT stands for artemisinin-based combination therapy.
🎯 Conclusion
Antimalarial drugs are an important topic for pharmacy examinations. Revise their classification, mechanisms of action, uses and adverse effects, and practise MCQs regularly to strengthen your preparation.
Disclaimer: This article is for educational purposes. Malaria can become life-threatening, so suspected infection requires prompt medical assessment and appropriate testing. Treatment must follow current national guidelines and professional advice.
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