8 Anti-Helmintics

Question 0

trematodes and cestodes are both considered flatworms but more specifically are

Answer 0

1. trematodes= flukes

2. cestodes=tapeworms

Question 1

what are the 3 groups of helminths

Answer 1

1. nematodes= round worms
2. trematodes= flat worms
3. cestodes= flat worms

Question 2

drugs for nematodes/roundworms

Answer 2

1. albendazole
2. pyrantel
3. thiabendazole
4. ivermectin
5. diethylcarbamazine

Question 3

albendazole is the DOC for–> nematodes/ roundworms=

Answer 3

1. whipworms= Trichuris trichura
2. pinworms= Enterobius vermicularis
3. hookworms= Necator americanus
4. round worms= Ascariasis lumbricoided

Question 4

MOA for albendazole= vs. nematodes/round worms

Answer 4

binds to and interferes with microtubules

decreases glucose uptake–> parasite being expelled in feces

Question 5

where is albendazole metabolized

Answer 5

liver

Question 6

if its pinworm…

Answer 6

give albendazole to everyone in the household–> treat everyone

Question 7

pyrantel (vs. nematodes/roundworms) is good vs.

Answer 7

1. round worms
2. pinworms
3. hookworms

BUT nowhere near as effective as albendazole

Question 8

what is the issue with pyrantel

Answer 8

its OTC drug–> so pts can self-medicate

Question 9

MOA pyrantel (for nematodes/roundworms)

Answer 9

depolarizing m. blocking agent

• -> its + parasites nicotinic receptors
• this paralyzes the worm which gets expelled by the hosts intestinal tract

Question 10

pyrantel is…

Answer 10

not advised in preg women bc there has been no established safety

Question 11

if you have pinworms, WHAT DO YOU DO?

Answer 11

treat the whole family and anyone that came in contact

Question 12

side effects of pyrantel (nematodes)

Answer 12

1. dizziness, headaches
2. abd cramps, vomiting
3. increased liver enzymes–>liver disease

Question 13

use thiabendazole (nematodes/roundworms) vs.

Answer 13

1. threadworms= strongyloides stercoralis
2. cutaneous larvae migrans= creeping eruption
3. early stages trichinosis= Trichinella spiralis

Question 14

MOA of thiabendazole

Answer 14

similar to albendazole?

-interferes with synthesis of parasites microtubules and decreases glucose intake

Question 15

side effects of thiabendazole

Answer 15

LIVER DAMAGE–> jaundice
-bad smelling urine

STEVEN-JOHNSON SYNDROME–> skin layers separate

Question 16

would you give thiabendazole to preg women?

Answer 16

NO

Question 17

ivermectin (nematode/roundworms)= DOC for

Answer 17

Onchocerca volvulus–> riverblindness/onchocerciasis

scabies

Question 18

MOA of ivermectin (river blindness)

Answer 18

targets GABA a receptors= mostly everywhere

–>causes Cl influx–> hyperpolarization–> paralysis of worm–> expelled

Question 19

characteristics of ivermectin (river blindness)

Answer 19

1. doesnt cross BBB
2. metabolized in liver
3. poop out

Question 20

side effects of ivermectin (river blindness<– nematode)

Answer 20

1. dizziness
2. diarrhea
3. LEUKOPENIA= decreased leukocytes

Question 21

if you rapidly start killing worms with ivermectin you will see…

Answer 21

worms in the whites of the eye= MAZZOTTI RXN

Question 22

when would it be contraindicated to give a pt ivermectin

Answer 22

if the patient is taking

1. benzos
2. barbs

or if the pt is pregnant

Question 23

Diethycarbamazine is the DOC for

Answer 23

treating filariasis= Wuchereria bancrofti

Question 24

MOA of diethylcarbamazine

Answer 24

decrease the muscular activity of parasites

Question 25

What drug would you use for a trematode (flatworm--> fluke) infections

Answer 25

praziquantel

Question 26

Praziquantel is the DOC for

Answer 26

1. schistosomiasis 2. trematodes= flatworms--> flukes 3. cestode (flatworms--> tapeworms) infections= cysticercosis

Question 27

MOA of praziquantel (used for trematodes and cestodes)

Answer 27

increase permeability of cell membrane to calcium | --> contracture and paralysis of parasite

Question 28

which antihelminth has significant 1st pass effect

Answer 28

praziquantel--> for trematodes and cestodes | -also metabolized by the liver

Question 29

contraindications for praziquantel

Answer 29

1. dont give to preg women | 2. dont use with cimetidine= p450 --> will increase plasma levels of praziquantel

Question 30

what else can praziquantel be used for?

Answer 30

cestodes= tapeworms 1. beef tapeworm 2. pork tapeworm 3. fish tapeworm SOUNDS LIKE CHINESE BUFFET

Question 31

how are trematodes and cestodes similar

Answer 31

they both lack a mouth and digestive tract

Question 32

praziquantel is the DOC for trematodes and cestodes in the US but in other countries the DOC for cestodes/tapeworms is...

Answer 32

niclosamide--> which - parasites mitochondrial anaerobic phosphorylation (uncouples the rxn from ADP to ATP

Question 33

what do you have to do before administering niclosamide

Answer 33

administer laxative prior to oral administration to purge bowel of dead segments AVOID ALCOHOL W/I 1 DAY OF ADMINISTRATION OF DRUG .COM