Antiparasitic Agents

Question 1

LUMINAL AGENTS

Answer 1

Act on parasite in bowel lumen
- diloxanide
- iodoquinol
- paromomycin

Question 2

Used as sole agent for asymptomatic amebiasis

Answer 2

Diloxanide Furoate

Question 3

Alternative to Diloxanide (long term use should be avoided due to risk of optic neuritis)

Answer 3

Iodoquinol

Question 4

Aminoglycoside antibiotic that can also be an alternative agent for cryptosporidiosis in AIDS patient (GI upset is common)

Answer 4

Paromomycin

Question 5

SYSTEMIC AGENTS

Answer 5

Active both in intestinal wall and liver
Chloroquine
Emetine/Dehydroemetine

Question 6

Eliminates trophozoites in liver abscesses

Answer 6

Chloroquine

Question 7

Backup drugs for severe intestinal or hepatic amebiasis (concentration in the liver reaches up to 1 month)

Answer 7

Emetine/dehydroemetine

Question 8

MIXED AGENTS

Answer 8

Active against both luminal & systemic disease
Metronidazole
Tinidazole

Question 9

DOC for invasive amebiasis (patients should still receive a luminal amebicide in addition to this)

Answer 9

Metronidazole

Question 10

Non-enzymatically reduced by reacting with reduced ferredoxin, which is cytotoxic to proteins & DNA

Answer 10

metronidazole MOA

Question 11

Metronidazole AE

Answer 11

AE: GI upset, Disulfiram-like reaction (avoid alcohol intake), unpleasant metallic taste

Question 12

2nd generation nitroimidazole similar to metronidazole but better tolerated with short term effects

Answer 12

Tinidazole

Question 13

DOC for asymptomatic intestinal disease

Answer 13

Diloxanide furoate

Question 14

DOC for mild-moderate intestinal disease

Answer 14

Diloxanide furoate + metronidazole

Alternate
Diloxanide furoate + tinidazole/ erythromycin/
Tetracycline

Question 15

DOC for severe intestinal disease

Answer 15

Diloxanide furoate + Metronidazole/ Tinidazole

Alternate
Diloxanide furoate + Emetine/ Dihydroemetine/ Tetracycline

Question 16

DOC for hepatic abscess & other extra intestinal disease

Answer 16

Diloxanide furoate + Metronidazole/ Tinidazole

Alternate
Diloxanide furoate + Emetine/ Dihydroemetine +
Chloroquine

Question 17

Toxoplasma gondii

Answer 17

Pyrimethamine + Sulfadiazine
Clindamycin

Question 18

Cryptosporidium

Answer 18

Nitazoxanide

Question 19

Giardiasis

Answer 19

Metronidazole

Question 20

Trichomoniasis

Answer 20

Metronidazole

Question 21

Primary Amebic Meningoencephalitis
(Naegleria fowleri)

Answer 21

Amphotericin B

Question 22

Leishmaniasis

Answer 22

Sodium Stibogluconate
Amphotericin B
Pentamidine

Question 23

African Sleeping sickness
(Trypanosoma Brucei)

Answer 23

Suramin in east Africa
Pentamidine in west Africa
Melarsoprol severe CNS disease

Question 24

Chagas disease
(Trypanosoma cruzi)

Answer 24

Benznidazole
Nifurtimox

Question 25

Babesiosis

Answer 25

Atovaquone + Azithromycin

Question 26

Inhibits microtubule synthesis & glucose uptake

Answer 26

Benzimidazoles - albendazole - mebendazole - thiabendazole

Question 27

DOC for cestodal infestations such as cysticercosis (Taenia solium) & hydatid cyst (Echinococcus granulosus)

Answer 27

Albendazole

Question 28

DOC for whipworm (Trichuris trichuria), pinworm (Enterobius vermicularis), hookworms (Necator americanus & Ancylostoma duodenale) & roundworm (Ascariasis lumbricoides)

Answer 28

Mebendazole

Question 29

More toxic than the other benzimidazoles; can cause CNS disturbances

Answer 29

Thiabendazole

Question 30

GABA agonist causing Cl- influx leading to hyperpolarization and eventual death of the parasite)

Answer 30

Ivermectins

Question 31

DOC for Onchocerciasis (Onchocerca volvulus), cutaneous larva migrans & strongyloides

Answer 31

Ivermectin

Question 32

AE: Mazotti-like reactions (fever, dizziness, somnolence, hypotension)

Answer 32

Ivermectin

Question 33

When is ivermectin contraindicated

Answer 33

Pregnancy and meningitis (can cross BBB)

Question 34

DOC for lymphatic filariasis, Loa-loa (eye-worm) & tropical eosinophilia

Answer 34

Diethylcarbamazine

Question 35

AE of diethylcarbamazine

Answer 35

Allergic reactions antihistamines or steroids can be co-administered to minimize the reactions associated

Question 36

Depolarizing, neuromuscular blocker causing persistent activation of parasite’s nicotinic receptors by release of Ach & acetylcholinesterase inhibition)

Answer 36

Pyrantel pamoate

Question 37

DOC for infections caused by roundworms, pinworms & hookworms

Answer 37

Pyrantel pamoate

Question 38

Increases cell membrane permeability to calcium leading to prolonged contraction & eventual paralysis of the worm musculature, resulting in the detachment of suckers from the tissue wall)

Answer 38

Praziquantel

Question 39

DOC for Schistosomiasis & most trematode & cestode infestation

Answer 39

Praziquantel

Question 40

Praziquantel AE

Answer 40

Drowsiness, dizziness, malaise & GI upset CX in pregnancy and nursing moms

Question 41

Inhibition of mitochondrial phosphorylation of ADP & anaerobic metabolism of the parasite; lethal for the scolex but not for the ova

Answer 41

Niclosamide

Question 42

2nd line treatment for cestodes

Answer 42

Niclosamide

Question 43

Laxative should be administered prior to giving this drug orally, to purge bowel of all dead segments in order to preclude digestion & liberation of ova (may lead to cysticercosis); alcoholic consumption should be avoided within the 1st day of treatment

Answer 43

Niclosamide

Question 44

Treat clonorchis sinensis

Answer 44

Praziquantel or albendazole