TB drugs

Question 1

second line TB drugs

Answer 1

fluorquinolines- levofloxacin, moxafloxacin

injectables- streptomycin, amikacin, capreomycin, kanamycin

core- ethionamide, PAS, cycolserine

Question 2

when should anti-TB drugs be discontined

Answer 2

if serum bilirubin is above or equal to 3 mg/dL or serum transaminase are more than 5x normal upper limit

Question 3

how long do you give the 4 drug combo of tb

Answer 3

8-9 weeks

Question 4

which of the TB drugs is cleared by kidney

Answer 4

ethambutol

Question 5

what is the enzyme that converts INH to active metabolite

Answer 5

catalase peroxidase (katG)

Question 6

what enzymes are inhibited by activated INH

Answer 6

KasA InhA

Question 7

resistance to INH

Answer 7

downregulation of katG or overexpression of KasA INHA

Question 8

2 major AE to INH

Answer 8

hepatic
-increased LFT, jaundice, hepatitis

-perihpheral neuropathy

Question 9

slow acetylators and INH, what meatbolite is reactive

Answer 9

N-acetyl-hydrazine and isonicotinic acid

Question 10

rifampin MOA

Answer 10

inhibits prokaryotic DNA dependent RNA polymeraes

bacteriidal, extracell and intracell

Question 11

resistance to rifampin

Answer 11

mutation of RNA poly

-drug permeability

Question 12

which drug can increase unplanned pregnancy bc of increased cyp450 meatbolizing OC

Answer 12

rifampin

Question 13

what is the substitute for rifampin in HIV/AIDS pts

Answer 13

rifabutin

Question 14

MOA pyrazinamide

Answer 14

uncertain- mycolic acid biosynthesis

Question 15

pyrazinamide reachers _____ pathogens and is bactericidal only at ____

Answer 15

intracellular

acidic pH

Question 16

ethambutol inhibits what enzyme

Answer 16

arabinosyl transferase

Question 17

which drugs can precipitate gout

Answer 17

ethambutol and pyrazinamide

Question 18

how does EMB cause hyperuricemia and urate crystals

Answer 18

blocks tubular secretion of urate

Question 19

treatment of latent TB

2 options

Answer 19

isoniazid and rifapentine for 3 months, once weekly

isoniazid for 9 months daily

Question 20

which of the 4 drugs is not recommended during preganancy

Answer 20

pyrazinamide

Question 21

MDR-TB is resistant to which 2 drugs

Answer 21

INH and rifampin

-use 2nd line

Question 22

____ should be used in combo with at least 3 other drugs to which MDR-TB isolate is susceptible

-MOA

Answer 22

bedaquiline

• inhibits mycobacterial adenosine 5- ATP synthase
• bactericidal