Anti-Parasitic therapy Flashcards
Tinidazole
toxicities:
dosing:
Uses:
toxicities:
Similar toxicities to Metronidazole
dosing:
More convenient dosing schedule
Oral only
Not FDA indicated for anaerobic infection, would not use for this purpose
Used for:
Amebiases
Trichomoniasis (relaspe or 2nd attempt, reinfection)
Giardiasis
Iodoquinal
mech:
absorption:
adverse:
spectrum
mech: unknown
absorption:
- poorly absorved oral formulation
- active in intestinal lumen
adverse:
nasuea, vomiting, rashes
spectrum:
-amebiasis tx only
- followup tx for severe amebiasis after a course of metronidazole
Nitazoxanide
mech:
admin:
adverse:
uses:
Mech:
interferes with electron transfer necessary for anaerobic metabolism
Admin:
oral only
Adverse:
Gi upset, headache
uses:
giardiasis
cryptosporidiosis
C. difficile
Hep C
not first line, expensive and not more effective that metro
Trypanosomiasis TX
T cruzi:
- nifurtimox (CDC only)
- Benznidazole (CDC only)
- available in South america
T. brucei gambiense:
- pentamidine or suramin (dont memorize)
- need CDC approval
- late disease treated with eflornithine and nifurtimox
T. Brucei rhodesiense: (dont memorize)
- suramin or melarsoprol
Chloroquine
Malaria chmoprophylaxis
- Quinacrine
- inhibits polymerization of hemozoin in PLasmodium food vacuole
- inexpensive
- only weekly dosing
- AEs: itching in Africans, vomiting, rashes
Widespread resistance of P. Falciparum
- Efflux pump reduces concentraiton in food vacuole
- REsistance restricts to select areas
Mefloquine (Larium)
- later generation quinacrine
- dosed weekly
- active against chloroquine reistant malaria
- Toxicities: vertigo, lightheadedness, neuropsychiatric (nightmares, psychosis, suicide)
better drugs avavilable
Doxycycline
dosed daily
Malaria prophylaxis
increased sun sensitvitiy, Gi upset not for children, pregrant women (staining of developing teeth)
Malaria self tx
Atovaquone proguanil
Mefloquine
Artemesinins
Less use of pyrimethamine sulfadoxine due to resistance, toxicities
rapid diagnostic tests on rise
Pryantel pamoate
Tx of pinworm, hookworm
Toxicities: GI upset, dizziness
Vet use
Lice, scabies (ectoparasites)
topical tx:
systemic tx:
topical:
- permethrin (Elimite, nix), insect neurotoxin
- Malathion
Systemic:
- ivermectin
summary
Metronidazole use for protozoa
Praziquantel, mebendazole, abendazole, ivermectin for worms
Ivermectin
uses:
Tx for:
- ascariasis, toxocariasis, cutaneous larva migrans
- onchocerciasis
- some filaria
- lice
Antiprotozoal treatments
metronidazole, tinidazole
iodoquinol
paromomycin
nitazoxanide
Metronidazole
mech:
distribution:
spectrum:
adverse:
Mech: Acts as an electron acceptor, once activated by reduction, it damages DNA and other macromolecules
Distribution:
penetrates well into all tissues
Spectrum:
highly bactericidal for anaerobic bacteria
protozoan infections:
trichomoniasis
Giardiasis
Amebiasis
Adverse:
beware of disulfiram-like reactions, metallic taste, neuropathy with prolonged use
Paromomycin
mech:
admin:
adverse:
uses:
mech:
proteins synthsis inhibitor, binds16s ribosomal RNA
admin:
oral only
adverse:
nausea, diarrhea, abdoinal pain
Uses:
amebiasis
alternative tx for leishmaniasis
Toxoplasmosis tx
- prophylaxis of reactivation in AIDS:
- treatment with ____ + _______.
trimethoprim sulfamethozazole- prophylaxis in AIDS patients
treament with prymethamin + sulfadiazine or clindamycin or atovaquone
Leishmaniasis
-visceral
- Liposomal amphotericin B (ergosterol in cell membrane)
- Sodium stibogluconate (pentavalent antimony)
- Paromomycin is an alternative
Atovaquone proguanil (malarone)
Malaria prolaxis
- expensive
- dosed daily
- atovaqone inhibit mitochondrial electron transport
- proguanil acts as a DHFR inhibitor
- toxicities: Gi upset, rash, well tolerated
Malaria tx
- uncomplicated for mild P. falciparum
atovaquone proguanil
artemther/ lumafantrine (coartem)
Artesunate (CDC)
Artemesinins
- tx of malaria
- chinese herbal derivatives- qinghaosa
- monotherapy not recommended
- emerging reisistence in SE asia
Quinine
tx of malaria
- quinine sulfate + doxycyline or clindamycin
Toxicity: flushing, tinnitus, confusion, cardiac conduction
- Mefloquine
Tx for severe Malaria
P. Falciparum
- quinidine gluconate IV
- Quinine dihyrdochloride IV
- plasma exchange in severe cerebral malaria
- close monitoring of volume status to avoid pulmonary edema due to capillary leak syndrome
Tx of P. vivax
reactivation prevented by followup tx with primaquine to kill hypnozoite stage in liver
- check GPD level to exclude deficiency prior to use to avoid hemolysis
praziquantel
**- **Antihelminthic tx
- unknown mech
- toxicities: GI upset, ab pain, rash
- tx of: schistosomiasis, chlonorchiasis, other flukes (not Fasiolahepatica)
Albendazole, Mebendazole
mech: inhibit tubulin polymerization, microtubule formation in worms
toxicities: GI upset, headache
Uses:
- pinworm, whipworm, hookworm, ascariasis
- echinoccocus, cysticercosis, trichinosis
- strongyloidiasis, toxocariasis, cutaneous larva migrans
- filaria
