Flashcards in Respiratory TB Deck (14):
Which antibiotics should TB be treated with for the first two months?
First two months:
Which antibiotics should TB be treated with for months 2-6?
side effects of Rifampicin?
-colours urine and all body fluids orange
-is a potent inducer of cytochrome enzymes (so rapid breakdown of all steroid hormones including hormonal contraception, similar breakdown of opiate analgesics and other drugs)
side effects of ethambutol?
-can cause optic neuritis (inflammation of the optic nerve)
Single agent drug resistance in TB
commonly to isoniazid
multi-drug resistance in TB
resistance to rifampicin and isoniazid
Extensive drug resistance in TB
multi-drug resistance (rifampicin and isoniazid) and also quinolones and injectable (a type of contraception?)
Name 2 tests which test for previous exposure to TB
-interferon gamma release assay (a blood test)
-mantoux (tuberculin) test (a skin test)
Mantoux AKA tuberculin skin test
-requires 2 visits (patient has to return to see if there has been a delayed hypersensitivity reaction at site of injection)
-detects previous exposure to either TB or BCG - so can give false positives
-cannot distinguish between latent TB, cured TB, active TB, and BCG
-reaction may be diminished in IC patients
interferon gamma release assay (IGRA)
This assay looks for interferon gamma specific to antigens found only in mycobacteria tuberculosis. It doesn't react with BCG.
-only requires 1 visit
Anti-TNF therapy is used for patients with Crohn's, rheumatoid, psoriasis, ankylosing spondylitis. Why should you look for latent TB before prescribing anti-TNF therapy?
Anti-TNF therapy can cause re-activation of latent TB - usually within the first 12 weeks
If patient has latent TB: they should be given 6 months of isoniazid or 3 months of isoniazid and rifampicin also.
-it's an attenuated strain of mycobacterium bovis
-most effective in neonates of high risk families
-also provides some protection against leprosy
What other infection should all TB patients be tested for?
Also: all HIV cases should be offered a chest x-ray to check for TB