Mycobacterial drugs, Antiparasitics, Antifungals

Question 1

PPD test or blood test positive, normal CXR, sputum smear negative, no sx - what type of TB?

Answer 1

latent TB Infection (not infectious)

Question 2

PPD+, abnormal CXR, sputum smear pos, presents with cough, fever, weight loss

Answer 2

TB disease (Active)

Question 3

drug that inhibits synthesis of mycolic acid

Answer 3

isoniazid

Question 4

mechanisms of resistance for isoniazid

Answer 4

1. lack of prodrug activation: mutated KAT G gene

2. overexpression of Inh A protein (mycolic acid synthesis)

Question 5

people who are slow acetylators (slow metabolism) are at greater risk for what when taking isoniazid?

Answer 5

more prone to develop toxicity–>peripheral neuropathy

Question 6

peripheral neuropathy and drug induced hepatitis are associated with what anti TB drug?

Answer 6

isoniazid,

Question 7

which anti TB drug exerts its effect by inhibtiing RNA synthesis?

Answer 7

rifampin

Question 8

GI disturbances, HA, dizziness, fatigue, hepatitis, red-orange urine/feces/sweat/tears/saliva are associaetd with?

Answer 8

rifampin

Question 9

what drug should rifampin be substituted with in HIV+ patients?

Answer 9

rifabutin

Question 10

what is a synthestic analogue of nicotinamide, a prodrug, and dependent on acidic environment?

Answer 10

pyrazinamide

Question 11

SE: hepatotoxicity, hyperuricemia

Answer 11

pyrazinamide

Question 12

drug that inhibits arabinosyl transferase, and is effective against active TB & MAC infxns

Answer 12

ethambutol

Question 13

AE: retrobulbar neuritis, hyperuricemia

Answer 13

ethambutol

Question 14

preferred regimen for active TB?

Answer 14

INITIAL PHASE: isoniazid + Rifampin + Ethambutol + Pyrazinamide
CONTINUATION PHASE: isoniazid + Rifampin

Question 15

preferred tx for latent TB?

Answer 15

isoniazid or rifampin

Question 16

what is one of the first drugs used when person is resistant to IREP?

Answer 16

streptomycin

Question 17

SE: ototoxicity (vertigo + hearing loss), nephrotoxicity

Answer 17

streptomycin

Question 18

which drug has a better activity against MAC organisms than rifampin?

Answer 18

rifabutin

Question 19

tx for MAC?

Answer 19

macrolide antibiotic + rifampin + ethambutol

Question 20

tx for leprosy?

Answer 20

dapsone + clofazimine + riframpin

Question 21

MOA: PFOR (convert pyruvate to acetyl CoA) activates prodrug under anaerobic conditions–>inhib protein/DNA synth

Answer 21

metronidazole

Question 22

what drug can be used to f/u tx of metronidazole to kill off the cysts of amebiasis?

Answer 22

iodoquionol or paramomycin

Question 23

HIV+, profuse watery diarrhea, from water submersion…what pathogen and how to tx?

Answer 23

pathogen: cryptosporidium parvum,
tx: Nitazoxanide

Question 24

contrast MOA of metronidazole + nitazoxanide

Answer 24

metronidazole: relies upon PFOR activates prodrug
nitazoxanide: inhibits PFOR

Question 25

how to tx toxo?

Answer 25

Pyrimethamine-Sulfadiazine

Question 26

how to tx PCP?

Answer 26

TMP-SMX

Question 27

which antimalarial can induce hemolytic anemia, esp in those with G6PD deficiency?

Answer 27

primaquine

Question 28

which component of malarone works by inhibiting DHFR?

Answer 28

proguanil

Question 29

which drug is commonly usef to tx river blindness?

Answer 29

ivermectin

Question 30

which Benzimidazoles has more efficient absorption, and can be used to tx cutaneous larval migrans, and strongyloidiasis?

Answer 30

Thiabendazole

Question 31

what is the drug of choice for treating any type of fluke infection?

Answer 31

praziquantel

Question 32

what unique characteristics do fungi have that can be targeted by drugs?

Answer 32

1. ergosterol instead of cholesterol | 2. fungal cell cell with glucans

Question 33

what antifungal has the broadest spectrum of activity?

Answer 33

amphotericin B

Question 34

how are liposomal packaged amphotericin B less toxic?

Answer 34

less interaction of drug with mammalian cell membreanes-->decr toxicity

Question 35

how do azoles function?

Answer 35

they all inhibit ergosterol synthesis

Question 36

what is the tx of choice for aspergillosis?

Answer 36

voriconazole

Question 37

what is flucytosine used to tx?

Answer 37

in combo tx for severe cryptococcal meningitis, some candida

Question 38

what type of fungi are echinocandins most effective against?

Answer 38

those with high amt of beta glucans in cell wall

Question 39

which antifungal becomes highly concentrated in hair, skin, and nails?

Answer 39

griseofulvin, terbinafine

Question 40

what is the 1st line tx of onchomycosis?

Answer 40

terbinafine

Question 41

which antifungals are available in topical preparations?

Answer 41

nystatin, clotrimazole, micronazole, terbinafine, naftifine

Question 42

unlike IREP, what is the cellular penetration of streptomycin

Answer 42

penetrates cells poorly-->only effective extracellularly

Question 43

iodoquinol and paromomycin are effective in eliminating e. histolytica from where?

Answer 43

the LUMEN of the intestine (NOT tissue)