BPS 437 Exam 2

Why is TB infection difficult to treat?

1. Slow growing: M. Tuberculossis doubling time is 24 hours

2. Dormant and Semi dormant cells complicate treatment. Dormant bacteria are resistant to nearly all antibiotics

3. Antibiotics work bset on rapidly dividing cells

4. Duration of therapy is months

5. Suscetptibility tests can take weeks, not days v

6. Drug Resistance

7. Drug Interactions 

8. Bacteria can live insdie our cells (some antibiotics have limited cell permeability) 

9. Unique Cell wall with hihg lipid content forms a sheild against drug entry 

What are the mechansims of drug resistance in mycobacteria

1. Unique Cell Wall

2. Dormancy

3. Mutation

4. Efflux Pump

What is the main treamtent of TB

1. Rifampin 

2. Isoniazid 

3. Pyrazinamide

4. Ethambutol

Is Isonazid bactericidal or bacteriostatic?

Both

Bacteriocidal against replicating M. tuberculosis

Bacteriostatic against semi dormant and dormant TB

Why is isoniazid sagfe to use as monotherapy in latent TB but not active TB

Latent TB has much lower organism than active tb, so the risk of redsistance developing is ar less 

Active TB requires multidrug therapy to prevent resistance 

What are adverse effects of Isoniazid

1. Hepatoxicity 

2. Peripheral Neuropathy 

What should you look out or in Hepatotoxicity of Isoniazid

Elevated Liver enzymes. Stop if there is jaudnice, abdominal pain or nausea.Limit alcohol to prevent additional hepatotoxicityl 

How can peripheral neuropathy be prevented

Pyridixoine (vitamin B6)