Mechanisms/Drug Class

Question 1

What is the mechanism of action of the antimalarial agents that inhibit heme metabolism?

Answer 1

Decrease the metabolism and/or removal of toxic heme products, resulting in increased toxicity to the plasmodia

Question 2

What is the mechanism of action of chloroquine?

Answer 2

Protonated chloroquine accumulates inside the parasite’s food vacuole, where it binds to ferriprotoporphyrin IX (heme) and inhibits its polymerization; accumulation of unpolymerized heme leads to oxidative membrane damage

Question 3

chloroquine

Answer 3

antimalarial agent: inhibitor of heme metabolism

Question 4

What is the mechanism of action of quinine?

Answer 4

Similar to chloroquine, but also intercalates into DNA

Question 5

quinine

Answer 5

antimalarial agent: inhibitor of heme metabolism

Question 6

quinidine

Answer 6

antimalarial agent: inhibitor of heme metabolism

Question 7

What is the mechanism of action of mefloquine?

Answer 7

Disrupts polymerization of heme to hemozoin inside intraerythrocytic malarial parasites

Question 8

mefloquine

Answer 8

antimalarial agent: inhibitor of heme metabolism

Question 9

What is the mechanism of action of artemisinin, artesunate, artemether, and dihydroartemisinin?

Answer 9

Form carbon-centered free radicals that alkylate heme

Question 10

arteminisinin

Answer 10

antimalarial agent: inhibitor of heme metabolism

Question 11

artesunate

Answer 11

antimalarial agent: inhibitor of heme metabolism

Question 12

artemether

Answer 12

antimalarial agent: inhibitor of heme metabolism

Question 13

dihydroartemisinin

Answer 13

antimalarial agent: inhibitor of heme metabolism

Question 14

What is the mechanism of action of the antimalarial agents that inhibit electron transport?

Answer 14

Inhibit the plasmodial electron transport chain

Question 15

What is the mechanism of action of primaquine?

Answer 15

Disrupts metabolism in plasmodial mitochondria, likely by inhibiting ubiquinone and by nonspecific oxidative damage

Question 16

primaquine

Answer 16

antimalarial agent: inhibitor of electron transport

Question 17

atovaquone

Answer 17

antimalarial agent: inhibitor of electron transport

Question 18

What is the mechanism of action of the antimalarial agents that inhibit translation?

Answer 18

Inhibit protein synthesis by binding to 30S ribosomal subunit (doxycycline and tetracycline) or 50S ribosomal subunit (clindamycin)

Question 19

doxycycline

Answer 19

antimalarial agent: inhibits translation

Question 20

tetracycline

Answer 20

antimalarial agent: inhibits translation

Question 21

clindamycin

Answer 21

antimalarial agent: inhibits translation

Question 22

What is the mechanism of action of sulfadoxine and sulfalene?

Answer 22

They are PABA analogues that competitively inhibit plasmodial dihydropteroate synthetase

Question 23

What is the mechanism of action of pyrimethamine?

Answer 23

It is a folate analogue that competitively inhibits plasmodial dihydrofolate reductase

Question 24

sulfadoxine-pyrimethamine

Answer 24

antimalarial agent: inhibitor of folate metabolism

Question 25

sulfalene-pyrimethamine

Answer 25

antimalarial agent: inhibitor of folate metabolism

Question 26

What is the mechanism of action of proguanil?

Answer 26

It is a pyrimidine derivative that inhibits plasmodial dihydrofolate reductase

Question 27

proguanil

Answer 27

antimalarial agent: inhibitor of folate metabolism

Question 28

What is the mechanism of action of metronidazole?

Answer 28

It is activated by enzymes in parasites and anaerobic bacteria to form reduced cytotoxic compounds that damage microbial proteins, membranes, and DNA

Question 29

metronidazole

Answer 29

antiprotozoal agent

Question 30

What is the mechanism of action of tinidazole?

Answer 30

A second-generation nitromidazole related to metronidazole; bout better tolerated and requires a shorter duration of treatment

Question 31

tinidazole

Answer 31

antiprotozoal agent

Question 32

What is the mechanism of action of nitazoxanide?

Answer 32

Inhibits the pyruvate-ferredoxin oxidoreductase (PFOR) enzyme that converts pyruvate to acetyl CoA in protozoa and anerobic bacteria

Question 33

nitazoxanide

Answer 33

antiprotozoal agent

Question 34

What is the mechanism of action of pentamidine?

Answer 34

Inhibits DNA, RNA, protein, and phospholipid synthesis, and dihydrofolate reductase activity

Question 35

pentamidine

Answer 35

antiprotozoal agent

Question 36

What is the mechanism of action of suramin?

Answer 36

Inhibits RNA-polymerase and glycerol phosphate dehydrogenase

Question 37

suramin

Answer 37

antiprotozoal agent

Question 38

What is the mechanism of action of melarsoprol?

Answer 38

Inhibits trypanosomal pyruvate kinase, thereby inhibiting glycolysis and decreasing ATP production; also inhibits adenine and adenosine uptake by trypanosomal transporters

Question 39

melarsoprol

Answer 39

antiprotozoal agent

Question 40

What is the mechanism of action of eflornithine?

Answer 40

Selective and irreversible inhibitor of ornithine decarboxylase

Question 41

elfornithine

Answer 41

antiprotozoal agent

Question 42

sodium stibogluconate

Answer 42

antiprotozoal agent

Question 43

meglumine antimonate

Answer 43

antiprotozoal agent

Question 44

What is the mechanism of action of miltefosine?

Answer 44

A synthetic ether phospholipid analogue similar to natural phospholipids in cell membranes; may inhibit enzyme systems associated with plasma membranes; may also inhibit platelet activating factor-induced responses and inosil phosphate formation

Question 45

miltefosine

Answer 45

antiprotozoal agent

Question 46

What is the mechanism of action of the antihelminthic agents?

Answer 46

All mechanisms lead to paralysis and death of worms

Question 47

What is the mechanism of action of ivermectin?

Answer 47

Potentiates both glutamate-gated chloride channels in nematode cell membranes and releases GBA from presynaptic terminals, leads to hyper polarization of neuromuscular cells and pharyngeal paralysis

Question 48

What is the mechanism of action of albendazole, mebendazole, and thiabendazole?

Answer 48

Inhibit tubulin polymerization by binding to beta-tubulin, causing degenerative changes in integumental and intestinal cells of helminths

Question 49

albendazole

Answer 49

antihelminthic agent

Question 50

ivermectin

Answer 50

antihelminthic agent

Question 51

mebendazole

Answer 51

antihelminthic agent

Question 52

thiabendazole

Answer 52

antihelminthic agent

Question 53

What is the mechanism of action of praziquantel?

Answer 53

Increases parasite membrane permeability to calcium, causing contraction and paralysis of worms

Question 54

praziquantel

Answer 54

antihelminthic agent

Question 55

diethylcarbamazine

Answer 55

antihelminthic agent

Question 56

What is the mechanism of action of pyrantel pamoate?

Answer 56

causes constant release of acetylcholine, causing persistent activation of parasite nicotinic acetylcholine receptors, causing tonic parlysis

Question 57

pyrantel pamoate

Answer 57

antihelminthic agent

Question 58

What is the mechanism of action of piperazine?

Answer 58

It is a GABA agonist that causes flaccid paralysis

Question 59

piperazine

Answer 59

antihelminthic agent