Tuberculosis

Question 1

treatment for active TB?

Answer 1

for 2 months;

• rifampicin
• isoniazid
• pyrazinamide
• ethanbutol

for 4 months;

• rifmapicin
• isoniazid

Question 2

treatment for latent TB?

Answer 2

either;
- rifampicin and isoniazid for 3 months
or
- isoniazid for 6 months

Question 3

what drug is co-prescribed with isoniazid and why ?

Answer 3

pyridoxine (vitamin B6)

prevents peripheral neuropathy which is a side effect of isoniazid

Question 4

side effects of rifampicin ?

Answer 4

potent liver enzyme inducer
heptaitis
orange secretions
flu like symptoms

Question 5

side effects of isoniazid ?

Answer 5

peripheral neuropathy
hepatitis
agranulocytosis
liver enzyme inhibitor

Question 6

side effects of pyrazinamide ?

Answer 6

hyperuricaemia = gout
arthralgia, myalgia
hepatitis

Question 7

side effects of ethambutol ?

Answer 7

optic neuritis

Question 8

gold standard investigation of choice for diagnosing active TB ?

Answer 8

sputum culture

Question 9

CXR features found in TB?

Answer 9

upper lobe cavitation (classical of reactivation of TB

bilateral hilar lymphadenopathy

Question 10

investigations for TB ?

Answer 10

CXR
sputum culture
sputum smear (Zeihl-Neilson stain)
NAAT

Question 11

screening tests for TB ?

Answer 11

mantoux test

interferon gamma blood test;
- if positive or equivocal, or patient has risk of false negative then

Question 12

risk factors for false negative mantoux test ?

Answer 12

miliary TB 
very young < 6 months 
sarcoidosis 
HIV 
lymphoma