ANTIMYCOBACTERIALS

Question 1

Antibacterial activity
• Gram-positive bacteria, gram-negative bacteria
(E. coli, Pseudomonas, Proteus, Klebsiella)
• BACTERICIDAL for Mycobacteria with good penetration into most tissues and phagocytic cells
• effective for both ACTIVE and LATENT forms of TB

Answer 1

RIFAMYCINS
Rifampin or Rifampicin (most commonly used), Rifapentine, Rifabutin

Question 2

Binds to the β subunit of bacterial DNA dependent RNA polymerase inhibiting RNA synthesis

Answer 2

RIFAMYCINS
Rifampin or Rifampicin (most commonly used), Rifapentine, Rifabutin

Question 3

• Rifampin (Rifampicin) best taken on an empty
stomach because absorption will be better.

Question 4

• Rifapentine best taken WITH food (not commonly
used)

Question 5

Undergoes enterohepatic recirculation

Answer 5

RIFAMYCINS

Question 6

• Mainly excreted in the feces as deacylated metabolites; a small amount is also excreted in the urine.
• No dose adjustments required for patients with renal disease or undergoing dialysis

Answer 6

RIFAMYCINS

Question 7

Harmless orange discoloration

o Liver enzymes are elevating more than 3 times or higher than the normal range → close monitoring of symptoms for cases of drug induced hepatotoxicity

Flu-like syndrome

CYP 450 inducer

Answer 7

RIFAMYCINS

Question 8

Used before as a prophylaxis for meningococcemia exposure, but now replaced by Ciprofloxacin

Answer 8

RIFAMYCINS

Question 9

• Antibacterial activity
  • Against Mycobacteria residing within the acidic environment of the lysosomes
• Activated under acidic conditions
• Converted to pyrazinoic acid (active form) by mycobacterial

Answer 9

PYRAZINAMIDE (PZA)