Treatment for TB

Question 1

First-line agents for TB

Answer 1

Rifampin
Isoniazid
Pyrazinamide
Ethambutol

Question 2

Mechanism of rifampin

Answer 2

Binds to beta subunit of bacterial DNA dependent RNA polymerase to inhibit RNA synthesis

Question 3

Bacterial resistance to rifampin

Answer 3

Point mutation in beta subunit gene
Decreased binding

Question 4

Contraindications of rifampin

Answer 4

Strong CYP450 inducer

Question 5

Drug for TB that turns urine, sweat, and tears orange

Answer 5

Rifampin

Question 6

Adverse effects of rifampin

Answer 6

Cholestatic jaundice
Hepatitis
Light-chain proteinuria
Flu-like syndrome
Acute tubular necrosis

Question 7

Drug that inhibits synthesis of mycolic acids after activation by bacterial catalase peroxidase

Answer 7

Isoniazid

Question 8

Bacterial resistance to isoniazid

Answer 8

Decreased KatG

Question 9

Drug for TB that is metabolized by liver N-acetyltransferase and thus affected by rapid vs slow acetylators

Answer 9

Isoniazid

Question 10

Adverse reactions of isoniazid

Answer 10

Hepatitis
Drug induced SLE
Peripheral neuropathy
Sideroblastic anemia

Question 11

Reason for peripheral neuropathy adverse effect of isoniazid

Answer 11

Relative pyridoxine deficiency

Question 12

How is pyrazinamide converted to pyrazinoic acid, its active form?

Answer 12

Mycobacterial pyrazinamidase

Question 13

Mechanism of pyrazinamide

Answer 13

Disrupts mycobacterial cell membrane metabolism and transport functions

Question 14

Bacterial resistance to pyrazinamide

Answer 14

Impaired uptake
Mutations in pyrazinamidase

Question 15

Adverse effects of pyrazinamide

Answer 15

Hepatoxicity
Hyperuricemia

Question 16

Drug that inhibits mycobacterial arabinosyl transferases and polymerization reaction of arabinoglycan

Answer 16

Ethambutol

Question 17

Bacterial resistance to ethambutol

Answer 17

Mutations resulting in overexpression of arabinosyl transferase gene

Question 18

Adverse reactions of ethambutol

Answer 18

Retrobulbar neuritis

Question 19

TB drug that can cause loss of visual acuity and red-green color blindness

Answer 19

Ethambutol

Question 20

Intensive phase of treatment for active TB infection

Answer 20

2 months of RIPE

Question 21

Continuation phase of treatment for active TB infection

Answer 21

Rifampin and isoniazid for 4 months

Question 22

Adjuvant treatment for active TB infection

Answer 22

Pyridoxine

Question 23

Treatment for latent TB infection

Answer 23

Isoniazid for 9 months

Question 24

Second-line drug for TB mainly active against EC tubercle bacilli

Answer 24

Streptomycin

Question 25

Site of action of streptomycin

Answer 25

30S subunit of ribosome

Question 26

Adverse effects of streptomycin

Answer 26

Ototoxic - vertigo and hearing loss Nephrotoxic

Question 27

Adverse effects of capreomycin

Answer 27

Nephrotoxic Ototoxic - tinnitus, deafness, vestibular disturbance

Question 28

Structural analog of D-alanine that inhibits wall synthesis. Used as a second-line treatment for TB.

Answer 28

Cycloserine

Question 29

Adverse effects of cycloserine

Answer 29

Peripheral neuropathy CNS dysfunction

Question 30

Adverse effects of ethionamide

Answer 30

Hepatotoxicity Neurologic symptoms

Question 31

Drug given to reduce/alleviate the neurologic side effects of cycloserine and ethionamide

Answer 31

Pyridoxine

Question 32

Mechanism of ethionamide

Answer 32

Blocks synthesis of mycolic acids

Question 33

Folate synthesis antagonist structurally similar to PABA and used as a second-line treatment for TB

Answer 33

Aminosalicylic acid (PAS)

Question 34

Bacterial RNA polymerase inhibitor often used in place of rifampin for treatment of TB in pts with HIV on antiretrovirals

Answer 34

Rifabutin

Question 35

Rifamycin that is a less potent CYP450 inducer

Answer 35

Rifabutine

Question 36

Effective short course treatment of latent TB when combined with isoniazid

Answer 36

Rifapentine

Question 37

Second-line drug for TB that inhibits ATP synthesis in mycobacteria

Answer 37

Bedaquiline

Question 38

Adverse effect of bedaquiline

Answer 38

QTc prolongation

Question 39

Second-line drug for TB that acts as a respiratory poison following NO release

Answer 39

Pretomanid