TB drugs - Mechanism of Action and Side Effects

Question 1

Which TB antibiotic inhibits RNA polymerase in bacteria?

Answer 1

Rifampicin = Rna Polymerase
=> prevents transcription of DNA

Question 2

Which TB antibiotic has the following side effects?:
- potent liver enzyme inducer
- hepatitis
- orange secretions
- flu-like symptoms

Answer 2

Rifampicin

Question 3

Mechanism of action of isoniazid

Answer 3

inhibits mycolic acid synthesis

ACID = isoniAZID

Question 4

Side effects of isoniazid

Answer 4

peripheral neuropathy
hepatitis
agranulocytosis
liver enzyme inhibitor

Question 5

Mechanism of action of pyrazinamide

Answer 5

Drug is converted by pyrazinamidase into pyrazinoic acid

=> inhibits fatty acid synthase (FAS)

Question 6

What TB antibiotic causes the following side effects?:
- hyperuricaemia (gout)
- arthralgia
- myalgia
- hepatitis

Answer 6

Pyrazinamide

Question 7

Mechanism of action of ethambutol

Answer 7

inhibits arabinosyl transferase which polymerizes arabinose into arabinan

Question 8

Side effects of ethambutol

Answer 8

optic neuritis

dose needs adjusting in patients with renal impairment

Answer 8

optic neuritis: check visual acuity before and during treatment
dose needs adjusting in patients with renal impairment