Tuberculosis Flashcards
1
Q
Stages of TB Infection
A
2
Q
How many have TB worldwide?
A
- 7 million
3
Q
Mycobacterium TB Structure
A
- Mycobacteria
- Surrounded by waxy layer, rich in lipids
- Ziehl-Neelsen Stain
- Anaerobic
- Non spore forming
- Non-motile
- Bacillus
4
Q
What is a Ziehl-Neelsen Stain?
A
- “Acid-fast stain”
5
Q
What do we use to treat TB?
A
- 6 months of treatment:
- Intensive phase - 2 months of 4 drugs
- R, H,Z & E
- Continuation phase - 4 months of 2 drugs
- R, I
6
Q
What is extra-pulmonary TB?
A
7
Q
How does Rifampicin (R) work?
A
- Binds to RNA polymerase
- Inhibits DNA transcription into mRNA
- Thus inhibits protein synthesis
- Bacteriocidal
- CYP 3A4 inducer
8
Q
What are the complications of Rifampicin?
A
- NEVER give it on its own
- It has loads of drug-drug interactions
- Reduces plasma drugs such as methadone and warfarin
- Therefore, patients are often prescribed lots of methadone alongside it.
9
Q
How does Isoniazid (H) work?
A
- Inhibits mycolic acid synthesis (fatty acids are part of Mycolata cell wall)
- Bacteriocidal
- CYP inhibitor (not as strong as Rifampicin)
10
Q
How does Ethambutol (E) work?
A
- Bacteriostatic - stops TB growing, but does not kill it altogether
- Cell wall inhibitor
- Inhibits arabiosyl transferase which polymerases arab….
11
Q
How does Pyrazinamide (Z) work?
A
- Officially unknown
- Inhibits fatty acid synthesis
- Acidifies inside of bacillus
12
Q
Complications of Pyrazinamide?
A
- Myalgia
- Gout
- Hepatitis
13
Q
What is Streptomycin?
A
*
14
Q
What are the 4 subpopulations of M.TB within the host?
A
- Extracellularly rapidly dividing
- Organisms that grow more slowly
- Organisms characterized by spurts of growth with periods of dormancy
- Dormant/persistent bacilli
15
Q
Treatment of latent TB
A
- 6-9 months of Isoniazid
