Anti-TB Agents

Question 1

first line TB agents

Answer 1

isoniazid, rifampin, pyrazinamide, ethamobutol, streptomycin

Question 2

most active drug against TB

Answer 2

isoniazid

Question 3

isoniazid MOA

Answer 3

inhibits synthesis of mycolic acids (mycobacterial cell wall)

covalent complex with AcpM and KasA

Question 4

resistance with isoniazid

Answer 4

overexpress inhA
mutation of katG
overexpress ahpC
mutation kasA

Question 5

adverse with INH

Answer 5

hepatitis - major toxic effect

peripheral neuropathy - B6 deficiency

Question 6

vit B6 deficiency

Answer 6

pyridoxine

with isoniazid tx

peripheral INH

Question 7

rifampin MOA

Answer 7

binds to beta-subunit of bacterial DNA-dependent RNA polymerase and inhibits RNA synthesis

bacteriacidal for mycobacterium

Question 8

resistance in rifampin

Answer 8

mutation of rpoB

Question 9

P450 inducer

Answer 9

rifampin

-may alter HIV NNRTI treatment

Question 10

red/orange urine color

Answer 10

rifampin

Question 11

pyrazinamide

Answer 11

MOA unknown
-active at pH 5.5

converted to pyrazinoic acid in macrophages

Question 12

pyrazinamide resistance

Answer 12

mutation of pncA

Question 13

most hepatotoxic first line agent

Answer 13

pyrazinamide

Question 14

ethambutol MOA

Answer 14

inhibit mycobacterial arabinosyl transferase - encoded by embCAB operon

involved in polymerization rxn of arabinoglycan - component of mycobacterial cell wall

Question 15

arabinoglycan

Answer 15

ethambutol inhibits this

Question 16

ethambutol resistance

Answer 16

overexpress emb gene

mutation of embB gene

Question 17

streptomycin

Answer 17

aminoglycoside

IM/IV administer

Question 18

streptomycin MOA

Answer 18

irreversible inhibitor of protein synthesis

binds S12 of 30S subunit

Question 19

streptomycin resistance

Answer 19

mutations in rspL gene or rrs gene

Question 20

streptomycin scope

Answer 20

mycobacterium tuberculosis
mycobacterium avium complex
mycobacterium kansasii

Question 21

vertical nystagmus

Answer 21

ethambutol

Question 22

vertigo and hearing loss

Answer 22

streptomycin

Question 23

severe/life-threatening TB

Answer 23

streptomycin

administered IV

Question 24

ethionamide

Answer 24

isoniazid second-line

Question 25

rifabutin

rifapentine

Answer 25

rifampin second-line

Question 26

amikacin
capremoycin
kanamycin

Answer 26

streptomycin second line

Question 27

leprosy drugs

Answer 27

clofazimine

dapsone

Question 28

four drug regimen

Answer 28

administered until susceptibility is determined

done bc drug resistant mutants are very frequent in population

Question 29

hepatotoxic drugs

Answer 29

INH, rifampin, pyrazinamide

pyrazinamide is most hepatotoxic

should be stopped - serum aminotransferase reaches 5x upper limit

Question 30

N-acetyltransferase

Answer 30

polymorphism at NAT2 cause variation in rate of acetylation

slow vs. fast acetylators

isoniazid biotransformation