TB drugs Flashcards
second line TB drugs
fluorquinolines- levofloxacin, moxafloxacin
injectables- streptomycin, amikacin, capreomycin, kanamycin
core- ethionamide, PAS, cycolserine
when should anti-TB drugs be discontined
if serum bilirubin is above or equal to 3 mg/dL or serum transaminase are more than 5x normal upper limit
how long do you give the 4 drug combo of tb
8-9 weeks
which of the TB drugs is cleared by kidney
ethambutol
what is the enzyme that converts INH to active metabolite
catalase peroxidase (katG)
what enzymes are inhibited by activated INH
KasA InhA
resistance to INH
downregulation of katG or overexpression of KasA INHA
2 major AE to INH
hepatic
-increased LFT, jaundice, hepatitis
-perihpheral neuropathy
slow acetylators and INH, what meatbolite is reactive
N-acetyl-hydrazine and isonicotinic acid
rifampin MOA
inhibits prokaryotic DNA dependent RNA polymeraes
bacteriidal, extracell and intracell
resistance to rifampin
mutation of RNA poly
-drug permeability
which drug can increase unplanned pregnancy bc of increased cyp450 meatbolizing OC
rifampin
what is the substitute for rifampin in HIV/AIDS pts
rifabutin
MOA pyrazinamide
uncertain- mycolic acid biosynthesis
pyrazinamide reachers _____ pathogens and is bactericidal only at ____
intracellular
acidic pH
ethambutol inhibits what enzyme
arabinosyl transferase
which drugs can precipitate gout
ethambutol and pyrazinamide
how does EMB cause hyperuricemia and urate crystals
blocks tubular secretion of urate
treatment of latent TB
2 options
isoniazid and rifapentine for 3 months, once weekly
isoniazid for 9 months daily
which of the 4 drugs is not recommended during preganancy
pyrazinamide
MDR-TB is resistant to which 2 drugs
INH and rifampin
-use 2nd line
____ should be used in combo with at least 3 other drugs to which MDR-TB isolate is susceptible
-MOA
bedaquiline
- inhibits mycobacterial adenosine 5- ATP synthase
- bactericidal
