Antimalarial & Antiparasitic Drugs

Question 1

How are lice transmitted?

Answer 1

Direct contact with an infested person or item.

Question 2

What population is most affected by lice?

Answer 2

Children aged 3–11 years.

Question 3

What is the mechanism of pyrethrin and pyrethroids?

Answer 3

Sodium channel agonists that overstimulate and paralyze lice.

Question 4

What is the mechanism of spinosad?

Answer 4

Nicotinic acetylcholine receptor agonist causing rapid neuronal excitation and death.

Question 5

What makes spinosad unique among lice treatments?

Answer 5

It kills both lice and unhatched eggs.

Question 6

What is the mechanism of malathion?

Answer 6

Organophosphate that inhibits acetylcholinesterase.

Question 7

What are common symptoms of lice infestation?

Answer 7

Itching caused by allergic reaction to bites.

Question 8

How are pinworms transmitted?

Answer 8

Fecal-oral route, especially in children.

Question 9

What is the diagnostic method for pinworm?

Answer 9

Tape test.

Question 10

What is the mechanism of benzimidazoles like albendazole and mebendazole?

Answer 10

Bind β-tubulin and inhibit microtubule polymerization.

Question 11

What is the mechanism of pyrantel pamoate?

Answer 11

Depolarizing neuromuscular blocking agent that paralyzes worms.

Question 12

What insect transmits malaria?

Answer 12

Female Anopheles mosquito.

Question 13

What are the two most common malaria-causing species?

Answer 13

Plasmodium falciparum and Plasmodium vivax.

Question 14

Which Plasmodium species cause relapsing malaria?

Answer 14

P. vivax and P. ovale.

Question 15

How does Plasmodium metabolize hemoglobin?

Answer 15

Degrades it in food vacuole, releasing toxic heme.

Question 16

How do 4-aminoquinolines work?

Answer 16

Prevent heme detoxification, causing toxic buildup in parasite.

Question 17

What is the active functional group in artemisinin?

Answer 17

Endoperoxide bridge.

Question 18

What is the proposed MOA of artemisinin?

Answer 18

Activation by heme iron generates free radicals that damage parasite proteins and membranes.

Question 19

Why is artemisinin paired with long-acting drugs?

Answer 19

Short half-life; reduces risk of recrudescence.

Question 20

What causes resistance to artemisinin?

Answer 20

Mutations in the Kelch 13 gene.

Question 21

What is the MOA of chloroquine?

Answer 21

Inhibits heme polymerization, leading to toxic heme buildup.

Question 22

What is a notable adverse effect of chloroquine?

Answer 22

Retinopathy.

Question 23

What causes chloroquine resistance?

Answer 23

Mutations in PfCRT1 and/or overexpression of PfMDR1.

Question 24

What is the MOA of primaquine?

Answer 24

Metabolized to ROS-generating quinoneimines that damage parasite mitochondria.

Question 25

What is primaquine used for?

Answer 25

Liver stages and hypnozoites of P. vivax and P. ovale.

Question 26

What is a key contraindication for primaquine?

Answer 26

G6PD deficiency due to hemolytic anemia risk.

Question 27

What is the MOA of doxycycline in malaria?

Answer 27

Inhibits apicoplast function and protein synthesis.

Question 28

What is doxycycline used for in malaria?

Answer 28

Prophylaxis and treatment of P. falciparum, often combined with quinine.

Question 29

What class is permethrin?

Answer 29

Pyrethroid.

Question 30

What is the MOA of permethrin?

Answer 30

Disrupts sodium channels causing delayed repolarization and paralysis.

Question 31

What is permethrin used for?

Answer 31

Topical treatment of lice and scabies.

Question 32

Is permethrin ovicidal?

Answer 32

No, it does not kill lice eggs.

Question 33

What class is spinosad?

Answer 33

Nicotinic acetylcholine receptor agonist.

Question 34

What is the MOA of spinosad?

Answer 34

Causes prolonged activation of nicotinic AChRs, leading to neuronal hyperexcitation and death.

Question 35

What is spinosad used for?

Answer 35

Lice infestation.

Question 36

Is spinosad ovicidal?

Answer 36

Yes, it kills both lice and unhatched eggs.

Question 37

What class is malathion?

Answer 37

Organophosphate insecticide.

Question 38

What is the MOA of malathion?

Answer 38

Inhibits acetylcholinesterase, causing overstimulation and paralysis.

Question 39

What is malathion used for?

Answer 39

Treatment of head lice.

Question 40

What is a notable safety issue with malathion?

Answer 40

It is flammable and has cholinergic toxicity risk if ingested.

Question 41

What class are albendazole and mebendazole?

Answer 41

Benzimidazoles.

Question 42

What is the MOA of albendazole?

Answer 42

Binds β-tubulin, inhibits microtubule polymerization and glucose uptake.

Question 43

What are albendazole and mebendazole used for?

Answer 43

Pinworms, roundworms, and other helminths.

Question 44

What are toxicities of albendazole?

Answer 44

GI upset, rare hepatotoxicity, bone marrow suppression with long use.

Question 45

What class is pyrantel pamoate?

Answer 45

Depolarizing neuromuscular blocker.

Question 46

What is the MOA of pyrantel pamoate?

Answer 46

Activates nicotinic receptors and causes spastic paralysis of worms.

Question 47

What is pyrantel pamoate used for?

Answer 47

Pinworms (Enterobius vermicularis).

Question 48

What class is chloroquine?

Answer 48

4-aminoquinoline.

Question 49

What is the MOA of chloroquine?

Answer 49

Inhibits heme polymerase; causes toxic heme accumulation.

Question 50

What is chloroquine used for?

Answer 50

Treatment and prophylaxis of sensitive Plasmodium spp.

Question 51

What is a major toxicity of chloroquine?

Answer 51

Retinopathy with long-term use.

Question 52

What class is artemisinin?

Answer 52

Endoperoxide antimalarial.

Question 53

What is the MOA of artemisinin?

Answer 53

Activated by iron to form free radicals that damage parasite proteins and membranes.

Question 54

What are artemisinin derivatives used for?

Answer 54

Treatment of P. falciparum malaria.

Question 55

Why is artemisinin combined with other agents?

Answer 55

To prevent resistance due to short half-life.

Question 56

What class is primaquine?

Answer 56

8-aminoquinoline.

Question 57

What is the MOA of primaquine?

Answer 57

Generates ROS and disrupts parasite mitochondria.

Question 58

What is primaquine used for?

Answer 58

Radical cure of P. vivax and P. ovale (hypnozoites).

Question 59

Who should not receive primaquine?

Answer 59

Patients with G6PD deficiency.

Question 60

What class is doxycycline?

Answer 60

Tetracycline antibiotic.

Question 61

What is the MOA of doxycycline in malaria?

Answer 61

Inhibits apicoplast protein synthesis.

Question 62

What is doxycycline used for in malaria?

Answer 62

Prophylaxis and adjunct therapy for P. falciparum.

Question 63

What are common toxicities of doxycycline?

Answer 63

Photosensitivity, GI upset, esophagitis.