TB drugs

Question 1

How is isoniazid activated?

Answer 1

Bacterial catalase-peroxidase (KatG)

Question 2

Is isoniazid bacteriostatic or bactericidal?

Answer 2

Bactericidal

Question 3

How does isoniazid cause cell death?

Answer 3

Decreases synthesis of mycolic acids…in cell wall

Question 4

What can isoniazid damage?

Answer 4

Neurotoxicity
Hepatotoxicity (this was emphasized)
Lupus

Question 5

What is something to keep in mind when dosing isoniazid?

Answer 5

The patient’s acetylation rate (fast vs. slow)…causes different half-lives

Question 6

Is rifampin bacteriostatic or bactericidal?

Answer 6

Bactericidal

Question 7

How does rifampin cause cell death?

Answer 7

Inhibits DNA-dependent RNA polymerase

Question 8

What side effects does rifampin have?

Answer 8

Hepatotoxicity–increases cytP450–messes up lots of drugs (cannot be given with HIV drugs)

Orange body fluids

Question 9

Should rifampin be given alone?

Answer 9

No…resistance develops

Question 10

Is pyrazinamide bacteriostatic or bactericidal?

Answer 10

Bactericidal

Question 11

How does pyrazinamide cause cell death?

Answer 11

Not fully known…may decrease pH in phagolysosomes

Question 12

What should be watched for when giving pyrazinamide?

Answer 12

Hyperuricemia

Hepatotoxicity

Question 13

Is ethambutol bacteriostatic or bactericidal?

Answer 13

Bacteriostatic

Question 14

How does ethambutol prevent the growth/reproduction of bacteria?

Answer 14

Block arabinosylatransferase–decreases carbohydrate polymerization of mycobacterium cell wall

Question 15

What can be seen with ethambutol?

Answer 15

Optic neuropathy–R/G color blindness

Question 16

What are types of aminoglycosides?

Answer 16

Gentamicin
Neomycin
Amikacin
Tobramycin
Streptomycin

“GNATS”

Question 17

Are aminoglycosides bacteriostatic or bactericidal?

Answer 17

Bactericidal

Question 18

How do aminoglycosides kill cells?

Answer 18

Inhibit formation of initiation complex
Cause misreading of mRNA
Block translocation

Question 19

Do aminoglycosides kill anaerobes or aerobes?

Answer 19

Aerobes–require O2 for uptake

Question 20

When else would aminoglycosides be used?

Answer 20

Severe gram- rod infections
Synergistic w/ beta-lactams
Bowel surgery (neomycin)

Question 21

What are side-effects to aminoglycosides?

Answer 21

Nephrotoxicity (particularly when given w/ cephalosporins)
Neuromuscular blockade
Ototoxicity (particularly when given w/ loop diuretics)
Teratogen

“caNNOT”

Question 22

What can cause resistance to aminoglycosides?

Answer 22

Transferase enzymes–acetylation, phosphorylation, or adenylation

Question 23

What is a mnemonic to remember the drugs, toxicity, and what it kills?

Answer 23

GNATS caNNOT kill anaerobes

Question 24

What do you give to prevent vitamin deficiency with Isoniazid treatment?

Answer 24

Pyridoxine (Vit B6) to prevent side effects.