Antimicrobials II

Question 1

How many people die each year from TB?

Answer 1

1.4 million worldwide

Question 2

What is the prevalence of TB in the United States?

Answer 2

3/100,000 native born

15/100,000 foreign born

Question 3

Resistance is most common in which TB drugs?

Answer 3

Ethambutol, isoniazid, and pyrazinamide

Question 4

What is the current recommendation for treatment of active TB?

Answer 4

All four drugs (ethambutol, isoniazid, pyrazinamide, and rifampin) for two months followed by isoniazid and rifampin for four months.

Question 5

Rifampin targets ______________.

Answer 5

DNA-dependent RNA polymerase

Question 6

Is isoniazid bacteriostatic or bactericidal?

Answer 6

For resting bacteria it is bacteriostatic and for growing bacteria it is bactericidal.

Question 7

Isoniazid is activated by _______________.

Answer 7

katG

Question 8

Where does isoniazid distribute to?

Answer 8

Everywhere in the body, including the CSF and caseating lesions

Question 9

Some people are able to ________________ isoniazid more quickly.

Answer 9

acetylate

Note: the U.S. population is about 50% slow and 50% fast. More Europeans are slow acetylators.

Question 10

After acetylation, isoniazid is _______________.

Answer 10

excreted in the urine

Question 11

The major form of resistance to rifampin occurs by ______________.

Answer 11

point mutations in RNA polymerase

Question 12

Which TB drug is excreted in bile?

Answer 12

Rifampin

Question 13

What side effects does rifampin have?

Answer 13

It makes body fluids orange.
CYP induction
Hepatotoxicity (particularly with other hepatitic damage)

Question 14

Ethambutol is bacter-____________.

Answer 14

ostatic (like ETHeL holding her hand up to stop the bucking horse)

Question 15

Ethambutol’s side effects include _____________.

Answer 15

optic neuritis with loss of color vision

Question 16

All of the anti-TB drugs have _____________ as a side effect.

Answer 16

hepatotoxicity (think of the Sketchy cow with the liver spot in the center of the scene)

Question 17

What are side effects of pyrazinamide?

Answer 17

GI upset, hepatotoxicity, and arthralgias

Question 18

____________ must be reported to the health department.

Answer 18

TB

Question 19

___________ binds to the beta subunit of DNA-dependent RNA polymerase.

Answer 19

Rifampin

Question 20

Like the NRTIs, rifampin can cause _____________.

Answer 20

mitochondrial damage (because it can target mitochondrial RNA polymerase)

Question 21

Pyrazinamide can cause what adverse effect that is unique among the TB drugs?

Answer 21

Hyperuricemia