Parasitic tx Flashcards
Metronidazole is drug of choice for what?
Giardiasis Severe amebiasis Trichomoniasis Pseudomembranous colitis Anaerobic bacteria
Adverse rxn for metronidazole
metallic taste
HA/nausea
peripheral neuropathy
Drug intxns with metrinidazole
alcohol (induces disulframic state)
disulfram
inducers of hepatic enzymes
tx for:
cryptosporidiosis (aids pts)
Leishmanias
Paromomycin (an AG) - [ ]ed in parasite in gut - inhibits protein synth (bind to A site on ribosome)
Tx for toxoplasmosis
Pyrimethamine + sulfadiazine
Pyrimethamine + clindamycin
- selectively targets parasitic enzymes
Diff targets of sulfonamide and TPM or pyrimethamine
TPM or pyrimethamine: inhibits DHFR
Sulfonamide: inhibits DHP synthase
Tx for pentamidine
- P. carinii pneumonia
- West african Trypanosomiasis
- Visceral Leishmanias
- accumulates in tissues
Adverse rxn of pentamidine
- Histamine release (rxn to dying organism)
- Hypotension
- Hypoglycemia
- Elevated AST/ALT
- Impaired renal fxn
Benzimadazoles inhibit _____
microtubule formation by bind to beta-tubulin and prevent formation of alpha/beta dimers
Which has better absorption, albendazole or mebendazole? Where is each excreted? WHich to avoid in pregnancy?
albendazole
- better absorption
- excreted in urine
*note that mebendazole is excreted in bile
avoid both in pregnancy
Tx for cysticercosis
pork tapeworm - taenia solium
albendazole
- has systemic absorption and is distributed into tissues
(unlike mebendazole where >95% is bound to plasma protein)
pyrantel pamoate
- MOA
- therapeutic use
- where does it [ ]?
ACh Receptor Agonist!
- so dont use piparazine (ACh R antag)
ascariasis (roundworm)
Enterobiasis (pinworm)
Hookworm infxn
- [ ]s in parasite
Mechanism of praziquantel
Ca2+ ionophore
- salt on preztle!
- induces paralysis in cestodes and trematodes –>
detachment, excretion
Therapeutic use of praziquantel
Cestodes (tapeworm)
Trematode (flukes)
What do you absolutely avoid when giving praziquantel?
Avoid if neurocystercicosis is present! or else . . .
- meningismus
- seizures
- CSF pleocytosis
Drug of choice for Plasmodium species
- where does it [ ]?
Chloroquine
(anticancer drug targeting autophagy)
[ ]s in food vacoules
Adverse rxn of chloroquine
If given via IV form, can have risk of very high dose
- Cardiovascular fx
- hypotension
- cardiac arrythmia
- cardiac arrest - CNS dysfxn
- confusion
- convulsion
- coma
Quinine is used when?
tx for erythrocytic stages of chloroquine resistant and multidrug resistant (MDR) P. falciparum malaria
Adverse rxns of quinine
- Chinchonism*
- visual, auditory, GI - stimulates pancreatic beta cells
- hyperinsulinemia
- hypoglycemia - Hypotension
When is mefloquine (quinine analog) used?
MDR P. faciparum
but quinine better
Proguanil/Atovaquone use
MDR malaria
Toxoplasma gondii
Malarone use
DHFR inhibitor
- but main fxn: somehow increases efficacy of atovaquone to collapse proton gradient
Only drug useful for latent forms of P. vivax and P. ovale
primaquine
When treating malaria, which drug to use: Not MDR: - Prophylaxis - Treatment MDR: - Prophylaxis - Tx
Not MDR:
- Prophylaxis: chloroquine phosphate (oral)
- Treatment: Chloroquin phosphate
MDR: - Prophylaxis: atovaquone/proguanil or doxy - Tx: Quinine + TCN or Pyrimethamine - Sulfadoxine + clindamycine
What do you have to make sure pts do not have if you are using primaquine?
G6PD def:
hemolytic anemia can be severe
