Anti-mycobacterial Drugs

Question 1

General Mycobacteria

Answer 1

Rod-like gram +

Form filamentous branching structures

Question 2

Why are mycobacteria difficult to treat?

Answer 2

Grow slowly
Cell walls= thick and impermeable
Reside in host cells–> difficult to reach therapeutic drug levels in mycobacterial cells
Acquire resistance quickly
IMPORTANT: to eradicate organism to obtain a cure

Question 3

Isoniazid

Answer 3

Inhibits synthesis of mycobacterial cell wall
(specific inhibits the mycolic acid component)

MOA: acetylation–fast acetylators may not reach target concentrations in plasma

Question 4

Rifampin

Answer 4

Inhibits bacterial RNA polymerase (similar to Riflaximin)

Induces drug metabolism, alters plasma drug concentrations–Major concern= drug-drug interactions

Question 5

Pyrazinamide

Answer 5

Anti-mycobacterial

unclear mechanism

Question 6

Ethambutol

Answer 6

Anti-mycobacterial

inhibits RNA synthesis

Question 7

Clofazimine

Answer 7

Binds DNA and inhibits RNA polymerase actions

Very slow bacteriocidal activities: treatment may take 2 years, possibly life