Anti TB drugs Flashcards Preview

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Flashcards in Anti TB drugs Deck (36)
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1
Q

Frontline TB drugs

A
  • Isoniazid
  • Rifampin
  • Ethambutol
  • Pyrazinamide
2
Q

Anti-TB drugs should be discontinued if what?

A

serum bilirubin is > or equal to 3 mg/dL

or

Serum transaminases are more than 5 times the upper limit of normal

3
Q

Goals of TB treatment

A
  • eradicate M. Tuberculosis infection
  • Prevent emergence of drug resistance
  • Prevent relapse of infection
4
Q

Describe the therapy necessary got TB to achieve the goals

A

prolong multi drug regimen

5
Q

How long do you use all 4 first line TB drugs and what phase is this

A

8 weeks . . intensive phase

6
Q

What drugs do you use after 8 weeks? and what phase is this

A

Isoniazid and Rifampin . . . continuation phase

7
Q

What is the purpose for the use of 4 drugs?

A

resistance

8
Q

Route of administration for TB drugs

A

oral

9
Q

What PARENTERAL drug is sometimes used in hospital setting in patients who cannot tolerate P.O. drugs

A

Streptomycin (aminoglycoside)

10
Q

Isoniazid is bactericidal in what type of TB?

A

growing

11
Q

isoniazid works by disrupting what?

A

mycolic acid synthesis

12
Q

What mycobacterial enzyme converts isoniazid into its active metabolite?

this then blocks what?

A

Catalase peroxidase (KatG)

InhA and KasA

13
Q

Isoniazid resistance mechanisms

A
  • depletion of katG

- overexpression/mutation of InhA and KasA

14
Q

What ethnicity are the fast acetylators of isoniazid

A

Asians

15
Q

What ethnicity are “slow acetylators” of isoniazid?

A
  • caucasians
  • Blacks
  • Hispanics
16
Q

What hepatic enzyme acetylates isoniazid

A

NAT

17
Q

2 Major adverse reactions to Isoniazid?

A

Hepatic

  • Elevated liver enzymes
  • Jaundice
  • Hepatitis

Neurologic

  • Peripheral neuritis (paresthesias)
  • convulsions
18
Q

Which acetylators get increased exposure to N-acetylhydrazine causing more hepatotoxicity

A

slow ones

19
Q

Isoniazid reacts convalently with ______ which depletes pools of what neurotransmitter leading the neuropathy

A

pyridoxal-5-phosphate

GABA

20
Q

What does Rifampin inhibit?

A

DNA dependent RNA polymerase

21
Q

Describe the characteristic of Rifampin effectiveness?

A

bacericidal even on SLOW GROWING bacteria

22
Q

Which Tb drug has high intracellular penetration?

A

Rifampin

23
Q

What TB drug stains things red/orange like urine, sweat, and contact lenses

A

Rifampin

24
Q

Which TB drug is a strong inducer of CYP enzymes and can increase clearance of oral contraceptives and can cause unplanned pregnancy/

A

Rifampin

25
Q

What drug would you substitute for Rifampin in HIV/AIDS patients

A

Rifabutin

26
Q

Which drug is narrow spectrum and is used for mycobacteria tuberculosis at ACIDIC pH

A

Pyrazinamide (PZA)

27
Q

What enzyme does Ethambutol inhibit?

A

Arabinosyl transferases and cell wall synthesis

28
Q

Adverse effects of ethambutol?

A
  • Visual (optic neuritis, color disturbance)

- Renal (gout)

29
Q

What TB drug blocks tubular secretion of urate leading to hyperuricemia and urate crystals

A

Ethambutol

30
Q

Treatment for Latent TB

A

isoniazid daily for 9 months

31
Q

What 3 drugs for TB are considered safe for pregnancy in the USA

A
  • isoniazid
  • Rifampin
  • ethambutol
32
Q

What is the leading killer of people who are HIV infected?

A

TB

33
Q

How do you go about treating a patient with TB and HIV

A
  • initiate TB treatment first, then HIV
  • Avoid weekly INH-rifapentine
  • Avoid twice weekly INH-rifampin if CD4 count <100
34
Q

What 2 drugs is multi drug resistant TB resistant to?

A

isoniazid and rifampin

35
Q

What are the second line drugs that can be used to treat MDR-TB

A

Fluoroquinolones - moxifloxacin and levofloxacin

Injectables - Amikacin, kanamycin, capreomycin, streptomycin

Add on or core 2nd line - Ethionamide, p-aminosalicyclic acid (PAS), cycloserine

36
Q

MOA of bedaquiline

A

inhibits mycobacterial ATP synthase