Tuberculosis pharmacology/therapeutics Flashcards Preview

PT3 ID 1 (HIV) > Tuberculosis pharmacology/therapeutics > Flashcards

Flashcards in Tuberculosis pharmacology/therapeutics Deck (48)
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1

how is tuberculosis spread

through the air in droplets

2

extrapulmonary tuberculosis

-tuberculosis infection that spreads beyond the lungs
-makes up about 15% of cases

3

mycobacterium tuberculosis features

-gm+
-mycolic acids make up outer membrane
-slow growing
-resides in macrophages
-rapidly develop resistance

4

what do drugs target in TB

cell wall/FAS

5

symptoms of active TB

-productive prolonged cough
-coughing up blood
-chest pain
-fever
-night sweats
-easily fatigued
-unexplained weight loss

6

symptoms of latent TB

-no obvious symptoms
-granulomatous lesions in lung

7

positive TST(PPD) for HIV infected/immunocompromised

>5 mm

8

positive TST(PPD) for high risk or injection drug user

>10 mm

9

positive TST(PPD) for person with no risk factors

>15 mm

10

TB vaccine

BCG
lasts 10-20 years

11

drug susceptibility test

MODS assay using sputum samples grows faster than normal cultures

12

1st line regimen for active TB infection

2 months: rifampin, isoniazid, pyrazinamide, ethambutol

then 4 months of: rifampin, isoniazid

13

isoniazid moa

inhibits biosynthesis of mycolic acids by binding to NAD to prevent elongation

14

isoniazid ADME

-rapidly absorbed
-t1/2 depends on fast or slow acetylators (1-3 hours)
-inhibits hepatic enzymes

15

isoniazid adverse effects

-peripheral neuropathy due to interference with pyridoxine (B6) metabolism, can be averted by Vit B6 supplements
-rarely hepatitis
-inhibits hepatic enzymes

16

rifampin moa

binds to beta-subunit of bacterial DNA dependent RNA polymerase preventing synthesis

17

rifampin ADME

-lipid-soluble
-t1/2 of 2-3 hours
-induces and inhibits 3A4

18

rifampin adverse effects

-reddish coloration of urine, tears, saliva
-flu like symptoms
-thrombocytopenia

19

rifampin drug interactions

-oral anticoagulants
-oral contraceptives
-methadone
*will need dosage changes*

20

ethambutol moa

inhibits cell wall by preventing mycolic acids from attaching to arabinogalactan

21

ethambutol ADME

t1/2 = 3-4

22

ethambutol adverse effects

optic neuritis that can lead to blindness if drug isn't stopped

23

pyrazinamide moa

binds ribosomal protein
*only in pH*

24

pyrazinamide ADME

half life of 10 hours

25

pyrazinamide adverse effects

-GI intolerance
-occasionally gout

26

multidrug resistant TB treatment

at least 4 effective drugs for 18-24 months

27

risk that a person will have active TB in life time

10%

28

how does PPD test work

tuberculin is injected and if the body has been exposed to TB the T cells are sensitized and mount a response

29

recent converter

based on reading 2 years ago:
for <35 PPD increases by more than 10 mm
for >35 PPD increases by >15 mm

30

who is at greatest risk of converting latent TB to active

-weak immune systems
-starting steroid use