9.1 Anti-Mycobacterials

Question 1

Ethambutol inhibits which enzymes?

Answer 1

arabinosyl transferases

Question 2

What is the most important Adverse Effect from Ethambutol?

Answer 2

• Dose-dependent visual disturbances (eg, red/green color blindness) – cannot be used in children too young to receive sight tests

Question 3

Which anti-mycobacterial drug has adverse effects of nongouty polyarthralgia?

Answer 3

Pyrazinamide

Question 4

What is the MOA of Pyrazinamide?

Answer 4

Enzymatically hyrolyzed to active pyrazinoic acid

Question 5

Which 3 drugs are recommended to be used in combination for Leprosy?

Answer 5

• Dapsone
• Clofazimine
• Rifampin

Question 6

What is the mechanism of Dapsone?

Answer 6

• Inhibits folate synthesis (via dihydropteroate synthetase

inhibition)

Question 7

What is acedapsone?

Answer 7

Repository form of dapsone

Question 8

What are the adverse effects of Dapsone?

Answer 8

• Hemolysis (esp. G6PD deficiency)
• Erythema nodosum leprosum (treated with
corticosteroids or thalidomide)
• Other effects – GI irritation, fever, hepatitis,
methemoglobinemia
• Other effects – GI irritation, fever, hepatitis,
methemoglobinemia
• CYP P450 inhibitor