Term
Albendazole
Mebendazole
Thiabendazole (topical)
- Mechanism
- Target organisms
- Pharmacokinetics
- Side effects |
|
Definition
Mechanism:
- paralyzes parasite via inhibition of microtubule polymerization by binding parasite β-tubulin
- blocks glucose uptake in larva and adults
- depletes glycogen and ATP by inhibiting fumarate reductase and uncoupling oxidative phosphorylation
- kill larvae only
Target organisms
- roundworms
- hydatid disease
- cysticerocosis
- pinworms
- Ascaris lumbricoides
- whipworm
- threadworm
- hookworms
- cutaneous larva migrans
- visceral larva migrans
- Trichinosis (early)
Pharmacokinetics:
- first pass metabolism in liver to albendazole sulfoxide, the active drug
Side effects:
- GI related
- dizziness
- elevation of liver transaminases
- contraindicated for children < 1 y/o or pregnant women in 1st trimester
- cirrhosis
- controversial in cysticercosis due to inflammatory rxn |
|
|
Term
Diethylcarbamazine
- Mechanism
- Target organisms
- Pharmacokinetics
- Side effects |
|
Definition
Mechanism:
- immobilizes mircofilariae
- kills babies
- mechanism against adult worms unknown
Target organisms:
- lymphatic filariasis (elephantiasis)
- scabies, lice, cutaneous larva migrans, ascarids also affected
Pharmacokinetics:
- rapid GI absorption
- 50% hepatic metabolism
- 50% renal excretion
Side effects:
- contraindicated for oncocerciasis (River blindness) |
|
|
Term
Ivermectin
- Mechanism
- Target organisms
- Pharmacokinetics
- Side effects |
|
Definition
Mechanism:
- intensifies GABA transmission (hyperactive Cl- channels) in nematode peripheral nerves
- anti-microfilaricidal
- keeps adults from making larva but doesn't kill them
Target organisms:
- onchocerciasis
- strongyloidiasis
- also scabies, lice, cutaneous larva migrans, ascarids
Pharmacokinetics:
- oral rapid absorption
- hepatic metabolism
- poor CNS penetration (eye)
Side effects:
- Mazzotti reaction = severe inflammatory rxn in tx of onchocerciasis; prevent w/ corticosteroids
- contraindicated in pregnancy, children < 5, w/ drugs that enhance GABA transmission |
|
|
Term
Praziquantel
- Mechanism
- Target organisms
- Pharmacokinetics
- Side effects |
|
Definition
Mechanism:
- increases Ca2+ permeability leading to paralysis, dislodgement, and death of adult tapeworms only: cestode/trematodes
Target organisms:
- schistosomiasis
- liver flukes
- adults tapeworms
- hydatid disease
- neurocytsocercosis (2nd line b/c it doesn't kill eggs)
Pharmacokinetics:
- poor CSF
- oral, rapid absorp
- excreted in urine, bile
- t 1/2 of 1.5 hrs
- increased absorption w/ carbohydrate meals
Side effects:
- GI
- Katayama fever = complication in Tx for schistosomiasis where dying immature worms exacerbate condition
- contraindications = preggers, kids < 5, drugs enhancing GABA transmission
|
|
|
Term
Pyrantel Pamoate
- Mechanism
- Target organisms
- Pharmacokinetics
- Side effects |
|
Definition
Mechanism:
- neuromuscular blocking agent elevates ACh, activates nicotinic receptors
- paralyzes worms allowing expulsion
- only good for intestinal worms
Target:
- pinworm
- Ascaris
- Trichostrongylus
- hookworms
- heavy worm burden patients
Pharmacokinetics:
- poor oral absorption = good for intraintestinal worms
- single dose
Side effects:
- GI
- contraindicated in hepatic disease, preggers, kids < 2 |
|
|
