Tuberculosis AB

Question 1

Isoniazid - what is the mechanism of action?

Answer 1

Inhibits mycolic acid synthesis

Bactericidal against actively dividing TB, bacteriostatic against resting bacteria

Question 2

Isoniazid - side effects?

Answer 2

Peripheral neuropathy (prevent with pyridoxine)
Hepatitis
Agranulocytosis
Liver enzyme inhibitor

Question 3

Rifampicin - what is the mechanism of action?

Answer 3

Inhibits RNA polymerase, preventing transcription of DNA to mRNA

Question 4

Rifampicin - side effects?

Answer 4

Orange secretions
Liver - hepatotoxicity and enzyme induction
Flu-like symptoms

Question 5

Pyrazinamide - mechanism?

Answer 5

Inhibits fatty acid synthesis

Question 6

Pyrazinamide - side effects?

Answer 6

Gout
Arthralgia
Hepatitis

Question 7

Ethambutol - mechanism?

Answer 7

May inhibit incorporation of mycolic acid into the mycobacterial cell wall.

Question 8

Ethambutol - side effects?

Answer 8

Optic neuritis

Question 9

What is the greatest risk of reactivation of TB?

Answer 9

HIV infection

Question 10

Which drugs may be used in pregnancy?

Answer 10

All of the first line drugs

Question 11

How long should you isolate patients who have been commenced on treatment for TB?

Answer 11

~2/52 (if getting better and compliant)

Question 12

Which anti-TB drugs cause hepatitis?

Answer 12

Isoniazid + Pyrazinamide

Rifampicin