TB

Question 1

Describe TB

Question 2

Why does TB occur

Answer 2

Wh

Question 3

What is the causative organism for TB

Question 4

List some risk factor for getting TB

Answer 4

Foreign born from highly endemic areas
Canadian Indigenous people
Close contacts
Homelessness
incarceration
Alcoholism, IVDU, malnutrition
Co-infection with HIV- TB and HIV act synergistically
< 2 yo and >56 yo
immunosuppression

Question 5

Describe the disproportionate impact of TB on FN, Inuit and Metis pop in Canada and Sask

Question 6

List some signs and sx for TB

Answer 6

Gradual onset
People may not seek medical attention until hemoptysis occurs – large cavities and large # organisms
Weight loss, fever, cough, fatigue, nightsweats
Frank hemoptysis
Chest exam – dullness to percussion, rales
Moderate ↑ WBC- lymphocyte predominance
CXR- nodular infiltrates (apices), cavitation

Question 7

What medication do you use extracellular - rapidly dividing; within cavities

Answer 7

isoniazid
rifampin
streptomycin

Question 8

What medication do you use within granulomas, semi dormant with occasional bursts of metabolic activity?

Answer 8

Pyrazinamide - best drug
rifampin and isoniazid

Question 9

What medication do you use with intracellular within macrophages for TB?

Answer 9

rifampin, INH, quinolones

Question 10

How do you tx for latent TB infection?

Answer 10

Rifampin daily x 4 months (4R)
Rifapentine and INH once weekly x 3 months (3HP)
If unable to use a rifamycin based regimen INH daily for 9 months (9H)
When 9H cannot be used - 6 month daily INH (6H)

Question 11

How do you tx for active TB infection?

Answer 11

2 main drugs are isoniazid and rifampin – used together whenever possible
Standard treatment is isoniazid, rifampin, pyrazinamide and ethambutol for 2 months followed by INH and RMP for 4 months – 6 months total
If sensitive to INH and RMP, ethambutol can be stopped at any time
Without pyrazinamide – a total of 9 months of RMP and INH required

Question 12

MOA of INH

Answer 12

inhibit bacterial wall synthesis
powerful early bactericidal activity

Question 13

Administration instructions for INH

Answer 13

empty stomach

Question 14

Adverse effects for INH

Answer 14

hepatotoxicity
neurotoxicity - peripheral neuropathy

Question 15

MOA of Rifampin

Answer 15

Inhibits bacterial RNA synthesis by binding to the beta subunit of DNA-dependent RNA polymerase, blocking RNA transcription

Same as rifabutin, rifapentine

Question 16

MOA of EMB

Answer 16

generally bacteriostatic, prevents drug resistance

Question 17

List the DDI with rifamycins

Answer 17

hormone therapy
levothyroxine
SSRI
Cort Steroids
oral anticoagulants

Question 18

Describe