Tuberculosis

Question 1

In mycobacteria the cell wall is composed of

Answer 1

mycolic acids

Question 2

The mycolic acids in mycobacteria are targets for what

Answer 2

drug targets

Question 3

What do you use to stain mycolic acids

Answer 3

acid-fast bacilli

Question 4

What two bacteria are responsible for TB?

Answer 4

M. tuberculosis

M. bovis

Question 5

What two bacteria are responsible for mycobacterium avium complex (MAC)?

Answer 5

M. avium

M. intracellulare

Question 6

How is TB transmitted?

Answer 6

coughing or sneezing from droplet nuclei

Question 7

3 phases of infection of TB

Answer 7

• primary
• latent tuberculosis infection
• active (re-activation) tb disease

Question 8

In LTBI, what is the evidence of infection?

Answer 8

• positive TST

- reactive IFN-gamma release assay

Question 9

Are patient contagious with LTBI?

Answer 9

no, not contagious

Question 10

What is active reactivation TB?

Answer 10

When LTBI becomes active (10%)

Question 11

Active TB onset and symptoms

Answer 11

productive cough lasting >3 weeks,
chills, fever, night sweats, fatigue
and weight loss, hemoptysis

Question 12

Is active TB contagious?

Answer 12

Yes, it is contagious

Question 13

How to diagnose active TB?

Answer 13

• positive TST
• positive blood test
• abnormal chest radiograph
• positive sputum smear or culture

Question 14

Treatment for TB?

Answer 14

Rifamycins:
◦ Rifampin (RIF)
◦ Rifabutin
◦ Rifapentine 
Isoniazid (INH) 
Pyrazinamide (PZA)
Ethambutol (EMB)

Question 15

Downside of RIPE therapy?

Answer 15

high pill burden (9 pills)

Question 16

Treatment principles for LTBI

Answer 16

1. Active disease should be ruled out before
   starting LTBI treatment
2. Monotherapy may be used (ONLY for LTBI)
3. Delay treatment during pregnancy

Question 17

First line therapy for LTBI?

Answer 17

Isoniazid 900mg & Rifapentine 900mg (3HP) once weekly for 3 months

Question 18

LTBI Second line therapy and used with pts with ioniazid resistance

Answer 18

Rifampin 600mg (RIF) daily for 4 months

Question 19

LTBI second line therapy

Answer 19

Isoniazid (INH) 300mg

daily for 6 or 9 months

Question 20

LTBI treatment with INH

Answer 20

Only 40-60% of those who initiate treatment for
LTBI with isoniazid (INH) for 9 months complete
therapy due to poor adherence, long treatment duration, and toxicity

Question 21

Advantages of 3HP + DOT?

Answer 21

• higher completion rates
• shorter duration
• less hepatotoxicity
• given once weekly

Question 22

Directly Observed Therapy (DOT)

Answer 22

-Health care worker watches patient swallow each
dose of medication
-can lead to reductions in relapse and drug
resistance
-use with other measures to promote adherence

Question 23

Treatment principles for active disease

Answer 23

1. patients should be isolated until no longer infectious
2. empiric therapy consists of multiple drugs
3. duration is dependent upon host factors, extent of disease, presence of resistance
4. never add a single drug to a failing regimen

Question 24

For RIPE therapy, rifampin and isoniazid is dosed on?

Answer 24

TBW

Question 25

For RIPE therapy, pyrazinamide and ethanbutol is dosed on

Answer 25

IBW

Question 26

Renal adjustments needed for which RIPE medications

Answer 26

PZA and EMB: Renal adjustment: CrCl < 30mL/min = dose 3x/wk

Question 27

Pyridoxine (vitamin B6) dose

Answer 27

25-50 mg daily

Question 28

Pyridoxine (vitamin B6) therapy needed in which pts

Answer 28

- alcoholsim - advanced age 65 or older - pregnancy - diabetes - CKD - autoimmune disease

Question 29

When TB is susceptible start on what therapy?

Answer 29

RIPE

Question 30

Initiation phase of TB

Answer 30

RIPE for two months

Question 31

Continuation phase of TB

Answer 31

INH and RIF for 4-9 months

Question 32

When do you extend continuation phase?

Answer 32

pts who are culture positive at 2 mo and immune suppressed pts (HIV, cavitary or extrapulmonary dx)

Question 33

Treatment adherence issues of TB

Answer 33

- long treatment duration - non-adherence - leads to resistance

Question 34

Because of drug-drug interactions when do you adjust dosings while taking with rifamycin

Answer 34

Adjust when rifamycin is started and ended

Question 35

Rifamycins are common CYP450 Inducers (increases | metabolism of other drugs to subtherapeutic levels) of what meds

Answer 35

Most HIV protease inhibitors Oral contraceptives Antifungals Methadone

Question 36

Isoniazid is an inhibitor (inhibits the metabolism of other drugs to toxic levels) which drugs

Answer 36

Phenytoin Carbamazepine Warfarin Benzodiazepine

Question 37

Mono-resistant

Answer 37

resistant to any one TB treatment drug

Question 38

Poly-resistant

Answer 38

resistant to at least any 2 TB drugs but not both INH and RIF

Question 39

Multidrug resistant MDR-TB

Answer 39

resistant to at least INH and RIF

Question 40

Extensively drug resistant XDR TB

Answer 40

resistant to INH and RIF plus to any fluoroquinolone and at least 1 of 3 injectable second line drugs (amikacin, kanamycin, or capreomycin)

Question 41

Preventing resistance

Answer 41

- use multi-drug regimens - promote medication adherence - monitor for intolerance or toxicities