Pharm of Antihelmintic and Ectoparasites

Question 1

what are the benzimidazoles

Answer 1

albendazole
mebendazole
thiabendazole

Question 2

moa of albendazole

Answer 2

inhibits microtubule synthesis, and has larvicidal effects in hydatid disease, cysticercosis, ascariasis, and hook worm.

ovicidal effects in ascariasis, ancylostomiasis, trichuriasis.

Question 3

absorption of albendazole

Answer 3

oral absorption is erratic and increases with a fatty meal. this means that you need to not have a fatty meal if intestinal (want to stay in the intestine) and YES have fatty meal if you want it to be absorbed (in the bloodstream)

Question 4

ADE albendazole

Answer 4

increases liver enzymes, pancytopenia

Question 5

MOA diethylcarbamazine (DEC)

Answer 5

immobilizes microfilaria and alters surface structure, used for filariases

Question 6

SE of DEC

Answer 6

limited, depend on number of microfilaria in the blood (once they are immobile, the body can start immune system and that’s when SE are seen)

Question 7

how to dose DEC

Answer 7

give initial low dose to reduce reaction to dying microfilariae, kills rapidly.

can only be obtained from the CDC

Question 8

clearance of diethylcarbamazine

Answer 8

renally cleared

is a base that gets reabsorbed when the urine is alkaline

(gets stick when urine is acidic)

Question 9

MOA ivermectin

Answer 9

induces tonic paralysis of musculature by activating glutamate-gated chloride channels and intensifying GABA mediated transmission of signals

Question 10

absorption of ivermectin

Answer 10

rapdily absorbed and wide tissue distribution, but doesn’t cross BBB

Question 11

spectrum ivermectin

Answer 11

broad vs roundworms (strongyloides, onchocerciasis, cutanous larvae, lymphatic filariasis, ectoparasites (scabies and lice)

Question 12

ADE ivermectin

Answer 12

mazzotti like reaction in filarial infection

Question 13

what is the mazotti like reaction?

Answer 13

intensity relates to microfilarial burden, basically is the immune system reacting to the filaria.

mostly mild itching, swollen tender lymph nodes that last a few days that is relieved by ASA and antihistamines

Question 14

what is pyrantel pamoate

Answer 14

induces persistent activation of nicotinic acetylcholine receptors and spastic paralysis and is poorly absorbed

Question 15

what is pyrantel pamoate effective for

Answer 15

pinworms, ascariasis, hookworms

Question 16

how to get pyrantel pamoate?

Answer 16

OTC –need to take once get it then wait for the worm life cycle to kill more

Question 17

MOA praziquantel

Answer 17

increase permeability of cell membranes to calcium and cause increased muscular activity followed by contraction and spastic paralysis.

Question 18

use for praziquantel

Answer 18

approved for schistosomiasis and liver fluke but also against trematodes and cestodes

need to manage inflammation

Question 19

what is permethrin

Answer 19

ectoparasite agent that interferes with sodium transport proteins causing neurotoxicity and paralysis

Question 20

resistance in permethrin?

Answer 20

resistance due to mutations reported in bed bugs so switch to ivermectin

Question 21

what is lindane

Answer 21

ectoparasite agent that induce neuronal hyperstimulation and eventual paralysis

Question 22

ADE of lindane

Answer 22

limit use bc increased potential for neurotoxicity in children and adults that are under 110lbs and in pt with underlying skin disorders