Antiprotozoals

Question 1

What is the DOC for symptomatic E. histolytica infx?

Answer 1

metronidazole + luminal amebicide

Question 2

What is the DOC for giardia lamblia?

Answer 2

metronidazole

Question 3

what is the dOC for trichomonas vaginalis?

Answer 3

metronidazole

Question 4

What is the DOC for toxoplasma gondii

Answer 4

pyrimethamine + sulfadiazine + folinic acid (leucovorin)

Question 5

what is the DOC for pneumocystitis jirovecii

Answer 5

TMP-SMZ + folinic acid (leucovorin)

Question 6

What are the major adverse reactions to metronidazole?

Answer 6

Dysguesia (metallic taste)

Disulfiram-like reaction

CNS/PNS sxs

Question 7

For patients with E. histolytica, G. lamblia and T. vaginalis infections who cannot tolerate metronidazole, what is the drug of second choice?

Answer 7

Tinidazole

Question 8

What is unique regarding the course of treatment with tinidazole vs. metronidazole?

Answer 8

Tinidazole has longer half-life and can be taken once daily

Question 9

Emetine and Dehydroemetine are only used under what conditions?

Answer 9

severe intestinal/systemic emebiasis infections where metronidazole is ineffective

Question 10

What limits the use of emetine/dehydroemetine?

Answer 10

cardiotoxicity, serious GI effects, teratogenicity.

only available under compassional use by CDC

Question 11

What are the DOC for asymptomatic e. hystolytica infections?

Answer 11

paramomycin or iodoquinol

Question 12

What toxicities accompany iodoquinol?

Answer 12

high iodine content can cause thyroid enlargement

nail/hair/skin/sweat discoloration

rare optic neuritis/atrophy

Question 13

paromomycin is what kind of antibiotic?

Answer 13

aminoglycoside

Question 14

why doesn’t paromomycin have oto/nephro toxicity?

Answer 14

because it is not absorbed from the GI tract

Question 15

when do you consider administration of iodoquinol or paromomycin?

Answer 15

for luminal trophozoites

Question 16

what is the main side effect for paromomycin?

Answer 16

GI upset or superinfection

Question 17

What common antibiotics are used as alternative drugs to treat amebiasis and giardiasis in combo with metronidazole?

Answer 17

tetracycline and erythromycin

Question 18

What is the DOC for toxoplasma gondii?

Answer 18

pyrimethamine/sulfadiazine + Leucovorin

Question 19

describe the dosage of pyrimethamine + sulfadiazine in the tx of toxoplasmosis

Answer 19

high dose, approaching the toxic level

Question 20

what is the DOC for pneumocystitis pneumonia from p. jirovecii infection?

Answer 20

TMP-SMZ

Question 21

What is often given as prophylaxis against p. jirovecii in AIDS patients?

Answer 21

TMP-SMZ

Question 22

what is pentamidine effective against?

Answer 22

p. jirovecii

Question 23

what is the mechanism of action for pentamidine?

Answer 23

inhibit DNA replication

Question 24

what are the toxic side effects of pentamidine?

Answer 24

hypotension, arrhythmia, hypoglycemia

Question 25

When should you consider using pentamidine for p. jirovecii?

Answer 25

when TMP-SMZ isn't able to be tolerated

Question 26

what is another drug that can be considered for patients with p. jirovecii that cannot tolerate TMP-SMZ or don't want to use pentamidine?

Answer 26

atavaquone + proguanil

Question 27

What drugs can be used to treat roundworms?

Answer 27

Albendazole, mebendazole, pyrantel pamoate or ivermectin

Question 28

What are the DOCs for roundworm infection?

Answer 28

Albendasole, mebendazole, or pyrantel pamoate

Question 29

alebendazole/mebedazole achieve success through what mechanism of action?

Answer 29

inhibit microtubule polymerzation and microtubule-dependent glucose uptake

Question 30

What is the mechanism of actio for pyrantel pamoate?

Answer 30

cholinesterase inhibitor, produces depolarizing neuromuscular blockade

Question 31

Ivermectin is effective against what parasites?

Answer 31

roundworms, insects and acarine parasites

Question 32

what is the mechanism of action for ivermectin?

Answer 32

paralytic, intensifies GABA mediated transmission of signals in peripheral nerves

Question 33

What is the DOC for tapeworms (cestodes) and flukes (trematodes)?

Answer 33

praziquantel

Question 34

What is the mechanism for action for praziquantel against tapeworms and flukes?

Answer 34

increases permeability to Ca.