TB drugs

Question 1

first-line TB drugs

Answer 1

use ALL 4:
1. isoniazid
2. rifampin
3. pyrazinamide
4. ethambutol

Question 2

isoniazid (first line TB drug) - mechanism of action

Answer 2

inhibits mycolic acid synthesis and catalase peroxidase

Question 3

isoniazid - mechanism of resistance

Answer 3

mutation or deletions in catalase-peroxidase or its regulating genes

Question 4

isoniazid - adverse reactions

Answer 4

1) HEPATITIS
2) peripheral neuropathy (give vitamin B6)

Question 5

rifampin (first line TB drug) - mechanism of action

Answer 5

inhibits bacterial DNA-dependent RNA polymerase

Question 6

rifampin - mechanism of resistance

Answer 6

mutation in RNA polymerase

Question 7

rifampin - adverse effects

Answer 7

*nausea/anorexia
*DRUG-DRUG interactions
*ORANGE color of urine and other body fluids

Question 8

pyrazinamide (first line TB drug) - results

Answer 8

results in RAPID decrease in number of viable organisms

Question 9

pyrazinamide - adverse effects

Answer 9

*hepatotoxicity
*increases urate concentration (avoid in Gout)

Question 10

ethambutol (first line TB drug) - mechanism of action

Answer 10

inhibits arabinosyl transferase that is necessary for cell wall biosynthesis

Question 11

ethambutol - adverse effects

Answer 11

*neuropathy
*retrobulbar (optic) neuritis!!

Question 12

moxifloxacin - 2nd line TB drug

Answer 12

*inhibits DNA gyrase inhibitor

Question 13

standard TB treatment regimen

Answer 13

first 2 months: isoniazid + rifampin + pyrazinamide + ethambutol
next 4 months: isoniazid + rifampin