mycobacterials

Question 1

mech of action of isoniazid

Answer 1

inhibits synthesis of mycolic acid. Delivered as prodrug, which is activated by mycobacterial catalase peroxidase enzyme (Kat G). Activated isoniazid forms covalent bond with at least 2 prtns involved in mycolic acid synthesis and impedes their function

Question 2

mech of action of rifampin

Answer 2

inhibits rna synthesis. binds bacterial dna dependent rna pol. does not affect mammalian rna pol

Question 3

rifampin adverse reactions

Answer 3

strong inducer of cytochrome P450

Question 4

Instead of rifampin in HIV pt, use what drug instead

Answer 4

Rifabutin

Question 5

Is pyrazinamide a prodrug

Answer 5

yes, converted to active form (pyrazinoic acid) by bacterial pyrazinamidase enzyme

Question 6

Mech of action of ethabutol

Answer 6

Inhibits arabinosyl transferases. Involved in mycobacterial cell wall synthesis

Question 7

Drug treatment regimen for leprosy

Answer 7

Dapsone, clofazimine and rifampin