Parasites and Protozoa and C diff Pharm

Question 1

Nematodes- drugs

Answer 1

• Albendazole

- Mebendazole

Question 2

Cestodes- drugs

Answer 2

• Albendazole
• Mebendazole
• Praziquantel

Question 3

Trematodes- drugs

Answer 3

-Praziquantel

Question 4

soil-transmitted helminths

Answer 4

• ascaris, hookworm, trichuris

- albendazole or mebendazole- Benzimidazoles!!

Question 5

Benzimidazoles- moa

Answer 5

bind to parasite B-tubulin- disrupt microtubule polymerization (stop mt dep processes- attachment, glucose-transport)

Question 6

Mebendazole- bioavailability, distribution

Answer 6

• poor absorption!! low systemic exposure!!

- stays in intestinal tract!!

Question 7

Albendazole- bioavailability, distribution

Answer 7

• modest absorption, efficient metabolism!!!- low systemic exposure
• hepatic metabolites!- so good for tissue dwelling helminths, hydatid cysts!!!

Question 8

Thiabendazole

Answer 8

-cutaneous use only!! for larval migrans (systemic toxicity)

Question 9

Mebendazole- treats what?

Answer 9

• enterobius vermicularis (pinworm)
• ascaris lumbricoides
• Trichuris trichiura (3 day course)

Question 10

Albendazole- treats

Answer 10

• Necator a, Ancylostoma d (hookworm)
• Ascaris lumbricoides
• Toxocara (larval migrans)

Question 11

Enterobius vermicularis (Pinworm)- drug

Answer 11

-Mebendazole

Question 12

Necator americanus, Ancylostoma duodenale (Hookworm)- drug

Answer 12

-Albendazole

Question 13

Ascaris lumbricoides- drug

Answer 13

• Albendazole

- Mebendazole

Question 14

Toxocara (Larval migrans)- drug

Answer 14

-Albendazole

Question 15

Trichuris trichiura (whipworm)- drug

Answer 15

• Mebendazole- *3 day course

- Albendazole

Question 16

Albendazole and mebendazole- contraindications

Answer 16

pregnancy- teratogenic!!!

Question 17

alternative nematode therapy

Answer 17

-pyrantel!!- hookworm, pinworm, roundworm (but not trichuris trichiura)

Question 18

pyrantel- moa

Answer 18

• depolarizing neuromuscular blocking agent

- causes act of N-AChR- spastic paralysis!!

Question 19

worm burden- heavy Ascaris infections- use what?

Answer 19

pyrantel!! with albendazole

Question 20

can be used in pregnant pts?

Answer 20

-pyrantel

Question 21

Ivermectin- used for?

Answer 21

• intestinal strongyloidiasis
• onchocerciasis- river blindness!!!
• lymphatic filariasis- Wuchereria bancrofti, Brugia malayi

Question 22

Ivermectin- moa

Answer 22

• act glutamate-gated Cl channels- hyperpolarization- paralysis
• cannot cross BBB in mammals
• can act on GABA-gated Cl channels in humans- so contraindicated if BBB is disrupted!!

Question 23

Diethylcarbamazine- used for?

Answer 23

• lymphatic filariasis

- loasis

Question 24

Cestodes (tapeworms)- infections

Answer 24

• Cysticercosis
• Echinococcosis
• Taeniasis- pork, beef
• Diphyllobrothriasis- fish

Question 25

drug for all adult form tapeworm infections

Answer 25

Praziquantel!! - taenia solium- pork - taenia saginata- beef - diphyllobothrium latum- fish

Question 26

drug for larval forms of tapeworm infections

Answer 26

Albendazole!! - cysticercosis - Echinococcus granulosus (Cystic hydatid dz)

Question 27

Cysticercosis (taenia solium tapeworm)- neuro sx's!!!- drug?

Answer 27

-Albendazole!!

Question 28

cystic hydatid dz (Echinococcus granulosus)- drug?

Answer 28

-Albendazole!!

Question 29

Schistosomiasis- drug?

Answer 29

-Praziquantel!!

Question 30

Praziquantel- moa

Answer 30

- interfere with Ca homeostasis and causes flaccid paralysis in adult flukes - causes ag's within the parasite to be exposed to the action of host ab's!!!

Question 31

Metronidazole- treats what?

Answer 31

-Entamoeba histolytica (amebiasis) -Giardia lamblia (anaerobic!!- PFOR complex activates the metronidazole!)

Question 32

treats giardiasis

Answer 32

-Tinidazole (resistance to metronidazole)

Question 33

Metronidazole- AE's

Answer 33

- metallic taste | - disulfiram-like rxn (sx's assoc w/ alcohol intake)

Question 34

E histolytica (amebiasis)- drug

Answer 34

- metronidazole! | - if sx- followed by a luminal amebicide to eliminate intraluminal cysts

Question 35

colonization of intestine with E histolytica- drug?

Answer 35

-Paromomicin

Question 36

C difficile- treatment?

Answer 36

- Metronidazole- initial choice - Vancomycin (PO)- 1st choice for recurrence - Fidaxomicin- ICU acquired