TB

Question 1

Phases

Answer 1

Treatment is split into 2 phases:
Initial phase
- 2 months
- 4 drugs

Continuation phase (4 months)
- 4 months
- 2 drugs

Question 2

Initial phase

Answer 2

RIPE
Rifampicin
Isoniazid (with pyridoxine)
Pyrazinamide
Ethambutol

Question 3

Continuation phase

Answer 3

Rifampicin
Isoniazid

Question 4

Rifampicin - SE

Answer 4

Common SE:
- N + V
- Thrombocytopenia

Specific:
- Psychosis
- Flu like symptoms with intermittent therapy
- Colours soft contact lenses AND urine red/orange

Question 5

Rifampicin - hepatic impairment

Answer 5

Caution
Dose reduction - max 8 mg/kg/day
Monitor weekly for 2 weeks, then fornightly for 6 weeks
Counsel pt to report signs of hepatotoxicty

Question 6

Rifampicin - Pregnancy + BF

Answer 6

Rifampicin = enzyme inducer = reduced efficacy of oral contraceptives (recommend IUD)
Pregnancy = high doses are teratogenic in 1st trimester, increased risk of neonatal bleeding in 3rd trimester.
BF = safe (amount too small to be harmful)

Question 7

Isoniazid - peripheral neuropathy

Answer 7

Pyridoxine given to prevent this SE.
More likely to occur with risk factors:
- Diabetes
- Alcohol dependance
- Renal failure
- Pregnancy
- HIV

Question 8

Isoniazid - pregnancy + BF

Answer 8

Pregnancy = not known to be harmful
BF = risk of convulsions and neuropathy, monitor infant for toxicity

Question 9

Pyrazinamide - contraindications

Answer 9

Gout

Question 10

Pyrazinamide - Pregnancy + BF

Answer 10

Pregnancy = only use if risk outweighs benefit
BF = amount too small to be harmful

Question 11

Ethambutol - contraindications

Answer 11

Optic neuritis
Poor vision

Question 12

Ethambutol - ocular toxicity

Answer 12

Counsel patient to report visual changes.
More common in high doses or renal impairment
Early discontinuation = recovery of eyesight

Question 13

Side effects - GENERAL

Answer 13

Liver toxicity = rifampicin, isoniazid + pyrazinamide
Peripheral neuropathy = isoniazid
Ocular toxicity = ethambutol
Orange/red secretions = Rifampicin