Mycobacterial drugs, Antiparasitics, Antifungals Flashcards
PPD test or blood test positive, normal CXR, sputum smear negative, no sx - what type of TB?
latent TB Infection (not infectious)
PPD+, abnormal CXR, sputum smear pos, presents with cough, fever, weight loss
TB disease (Active)
drug that inhibits synthesis of mycolic acid
isoniazid
mechanisms of resistance for isoniazid
- lack of prodrug activation: mutated KAT G gene
2. overexpression of Inh A protein (mycolic acid synthesis)
people who are slow acetylators (slow metabolism) are at greater risk for what when taking isoniazid?
more prone to develop toxicity–>peripheral neuropathy
peripheral neuropathy and drug induced hepatitis are associated with what anti TB drug?
isoniazid,
which anti TB drug exerts its effect by inhibtiing RNA synthesis?
rifampin
GI disturbances, HA, dizziness, fatigue, hepatitis, red-orange urine/feces/sweat/tears/saliva are associaetd with?
rifampin
what drug should rifampin be substituted with in HIV+ patients?
rifabutin
what is a synthestic analogue of nicotinamide, a prodrug, and dependent on acidic environment?
pyrazinamide
SE: hepatotoxicity, hyperuricemia
pyrazinamide
drug that inhibits arabinosyl transferase, and is effective against active TB & MAC infxns
ethambutol
AE: retrobulbar neuritis, hyperuricemia
ethambutol
preferred regimen for active TB?
INITIAL PHASE: isoniazid + Rifampin + Ethambutol + Pyrazinamide
CONTINUATION PHASE: isoniazid + Rifampin
preferred tx for latent TB?
isoniazid or rifampin
what is one of the first drugs used when person is resistant to IREP?
streptomycin
SE: ototoxicity (vertigo + hearing loss), nephrotoxicity
streptomycin
which drug has a better activity against MAC organisms than rifampin?
rifabutin
tx for MAC?
macrolide antibiotic + rifampin + ethambutol
tx for leprosy?
dapsone + clofazimine + riframpin
MOA: PFOR (convert pyruvate to acetyl CoA) activates prodrug under anaerobic conditions–>inhib protein/DNA synth
metronidazole
what drug can be used to f/u tx of metronidazole to kill off the cysts of amebiasis?
iodoquionol or paramomycin
HIV+, profuse watery diarrhea, from water submersion…what pathogen and how to tx?
pathogen: cryptosporidium parvum,
tx: Nitazoxanide
contrast MOA of metronidazole + nitazoxanide
metronidazole: relies upon PFOR activates prodrug
nitazoxanide: inhibits PFOR
how to tx toxo?
Pyrimethamine-Sulfadiazine
how to tx PCP?
TMP-SMX
which antimalarial can induce hemolytic anemia, esp in those with G6PD deficiency?
primaquine
which component of malarone works by inhibiting DHFR?
proguanil
which drug is commonly usef to tx river blindness?
ivermectin
which Benzimidazoles has more efficient absorption, and can be used to tx cutaneous larval migrans, and strongyloidiasis?
Thiabendazole
what is the drug of choice for treating any type of fluke infection?
praziquantel
what unique characteristics do fungi have that can be targeted by drugs?
- ergosterol instead of cholesterol
2. fungal cell cell with glucans
what antifungal has the broadest spectrum of activity?
amphotericin B
how are liposomal packaged amphotericin B less toxic?
less interaction of drug with mammalian cell membreanes–>decr toxicity
how do azoles function?
they all inhibit ergosterol synthesis
what is the tx of choice for aspergillosis?
voriconazole
what is flucytosine used to tx?
in combo tx for severe cryptococcal meningitis, some candida
what type of fungi are echinocandins most effective against?
those with high amt of beta glucans in cell wall
which antifungal becomes highly concentrated in hair, skin, and nails?
griseofulvin, terbinafine
what is the 1st line tx of onchomycosis?
terbinafine
which antifungals are available in topical preparations?
nystatin, clotrimazole, micronazole, terbinafine, naftifine
unlike IREP, what is the cellular penetration of streptomycin
penetrates cells poorly–>only effective extracellularly
iodoquinol and paromomycin are effective in eliminating e. histolytica from where?
the LUMEN of the intestine (NOT tissue)
