Antiprotozoals Flashcards
Mixed amebicide (luminal + systemic activity)
Metronidazole
Tinidazole
They are completely absorbed in the GI however, so least effective at luminal level.
Chloroquine
Dehydroemetine & Emetine
Part of what class of antiprotozoals ?
Systemic amebicides
Totally absorbed in GIT, no action in the lumen.
Examples of luminal amebicides ?
Paromomycin
Iodoquinol
Systemic amebicides are effective at what level ?
Tissue level (interstinal wall, liver mostly)
Effective both against protozal infections and anaerobic bacterial infections ?
Metronidazole
Achieves high concentration in the liver & CNS
Bacterial use : fragilis, c diff and h pylori
* Metronidazole no longer DOC for c diff ; replaced by Vancomycin
DOC for treatment of Entamoeba histolytica, Giardia lambia and Trichomonas vaginalis ?
Metronidazole
x 7-14 days
Main side effects of Metronidazole ?
GI (alteration of microbiome)
Metallic taste
Peripheral neuropathy
Disulfiram-like reactions
Teratogenic
Short acting version of Metronidazole ?
Tinidazole
Better tolerance ; single dose daily for shorter duration - 5 days
ONLY FOR PROTOZOAL INFECTIONS
NOT USEFUL IN ANAEROBIC BACTERIAL INFECTIONS UNLIKE METRONIDAZOLE
What is the basis of treatment for asymptomatic protozoal infections ?
Luminal amebicides
Tissue amebicidal drugs (e.g. metronidazole) should always be combined with what to prevent relapse ?
Luminal amebicides
Paromomycin (aminoglycosides) is a :
Luminal amebicide
Luminal amebicide useful in the treatment of Giardia lambia when Metronidazole is contraindicated ; in AIDS pts with cryptosporidiosis or cutaneous leishmaniasis ?
Paromomycin
Luminal amebicide that can cause NoVo, thyroid enlargment and optic neuritis (blindness) as side effects ?
Iodoquinol
Nitazoxanide antiprotozoal effective in treatment of giardiasis and cryptosporidiosis MAO ?
Inhibits PFOR pathway of electron transport
Systemic amebicide that highly concentrated in the liver & kills trophozoites, used in amebic liver abscess in combination with Metronidazole and Paromomycin/Iodiquinol ?
Chloriquine
Last resort systemic amebicides (cardiotoxicity, contraindicated in arrythmias) if other drugs are ineffective or in treatment of severe intestinal hepatic/extraintestinal amebiasis :
Emetine & Dehydroemetine
IM injection
Treatment of Entameba histolytica infection :
DOC for toxoplasmosis?
Perimethamine & sulfadiazine in combination.
Blocks steps of folic acid synthesis and together synergistic effect
Megaloblastic anemia –> prevent with leucovorin (folinic acid)
DOC for prophylaxis & trx of T toxoplasmosis as well as lifelong prophylaxis for pneomocystitis pneumonia (jerovecii) in AIDS pts ?
Pyrimethamine & Sulfadiazine combination
Toxoplasmosis during pregnancy treat with ?
Spiramycin (macrolide)
Nitazoxanide, Paromomycin & Azithromycin are useful in treatment of :
Cryptosporidiosis
Treatment of tyrpanosomiasis
Aerosol or IM, not IV (hypotension, tachy)
Can cause severe renal dysfunction & hypoglycemia
Pentamidine
DOC in early hemo-lymphatic stage of West African trypanosomiasis ?
DOES NOT CROSS BBB
Pentamidine
Alternate drug to sitbogluconate in treatment of visceral Leishmaniasis & inhalation form once of month for prophylaxis of Pneumocystosis (jirovecii) in AIDS pts ?
Pentamidine
Used in African trypanosomiasis
IV route
Does not cross BBB so not usefull in advanced stages
Can cause proteinuria/hematuria
Suramin
DOC in advanced CNS meningo-encephalitic stage of East African trypanosomiasis (sleeping sickness) ? second line in West African ?
Melarsoprol
Side effects of Melarsoprol:
Highly toxic & morbidity
Immediate : HSR & GI disturbances
CNS toxicity : fatal reactive encephalopathy
Later : renal & cardiac diseases
Used in West African TP in combination with Nifurtimox
Eflornithine
Suicide substrate
DOC in T cruzii (Chagas disease) which MAO is inhibition of trypanothione reductase thus DNA synthesis ?
American trypanosomiasis
Nifurtimox & Benznidazole
DECREASE THE SEVERITY OF THE PARASITE, BUT NOT EFFECTIVE FOR ERADICATION
DOC for West African TP early & advanced stages
Fexinidazole
Early : Fexinidazole
Late CNS : Fexinidazole + Eflornithine + Nifurtimox