Antibiotics: Antimycobacterials

Question 1

Drugs used for an Active TB infection

Answer 1

Isoniazid, rifampin, pyrazinamide, ethanbutol.

Question 2

TB Multiple drug resistance to these drugs…

Answer 2

isoniazid, rifampin

Question 3

TB extreme drug resistance to these drugs…

Answer 3

isoniazid, rifampin, fluoroquinolones, injectable second-line drugs.

Question 4

TB Treatment (0-2 months)

Answer 4

isoniazid, rifampin, pyrazinamide, ethanbutol.

Question 5

TB Treatment (2-6 months)

Answer 5

Isoniazid and rifampin.

Question 6

Latent TB treatment

Answer 6

Monotherapy with either isonizaid or rifampin

Question 7

Isoniazid MOA

Answer 7

Inhibits mycolic acid biosynthesis. Prodrug that becomes active within the bacilli. Given orally.

Question 8

Isoniazid Metabolismq

Answer 8

metabolized through acetylation in the liver. bimodal distribution in terms of fast and slow acetylators.

Question 9

Fast acetylators

Answer 9

eskimos, native americans and asians.

Question 10

Isoniazid toxicities

Answer 10

Hepatitis (especially fast acetylators), peripheral neuritis (especially slow acetylators), hemolysis (G6PD), Lupus like syndrome, CNS stimulation.

Question 11

Lupus like syndrome drugs

Answer 11

Hydralazine, isoniazid, procainamide

Question 12

Rifampin MOA

Answer 12

inhibits DNA dependent RNA polymerase. given orally.

Question 13

Rifampin spectrum

Answer 13

TB (active and latent), Leprosy, most gram positive cocci and some gram negative organisms.

Question 14

Rifampin toxicities

Answer 14

hepatic enzyme inducer: VERY strong inducer of P450s. Causes drug interactions especially in HIV positive patients who are taking protease inhibitors.
Harmless orange color to body fluids
Decreases the effectiveness of birth control by inducing the metabolism of progestins.

Question 15

Ethambutol MOA

Answer 15

Inhibits arabinosyl transferases that are involved in the synthesis or arabinogalactan in the mycobacteria cell wall. given orally. Great penetration of the CNS.

Question 16

Ethambutal elimination

Answer 16

renal elimination. Renal dosing needed in cases of renal insufficiency.

Question 17

Ethambutal toxicities

Answer 17

Decreased visual acuity and loss of green/red perception. Not recommended in children under 13.

Question 18

Pyrazinamide MOA

Answer 18

Prodrug with unknown mechanism. Very active at acidic pH like the environment of the macrophage. Active against dormant organisms.

Question 19

Pyrazinamide toxicities

Answer 19

hepatic dysfunction

Question 20

Streptomycin MOA

Answer 20

Protein synthesis inhibitor of 30S ribosome.

Question 21

Streptomycin toxicities

Answer 21

ototoxicity and nephrotoxicity.

Question 22

streptomycin and TB

Answer 22

Used as a first line drug for drug resistant strains.

Question 23

Rifabutin uses

Answer 23

Replaces rifampin in HIV-TB coinfected patients. Less potent inhibitor of P450s.

Question 24

Rifabutin MOA

Answer 24

Same as Rifampin. Inhibits RNA polymerase.

Question 25

Para-aminosalicyclic acid

Answer 25

second line TB drug

Question 26

Ethionamide

Answer 26

second line TB drug

Question 27

Capreomycin

Answer 27

second line TB drug

Question 28

Amikacin

Answer 28

second line TB drug

Question 29

Fluoroquinolones

Answer 29

second line TB drug

Question 30

Mycobacterium avium complex (MAC) etiology

Answer 30

M. avium and M. intracellulare

Question 31

MAC treatment

Answer 31

1. clarithromycin or azithromycin
2. ethambutol
3. rifabutin, rifampin or ciprofloxacin

Question 32

PB leprosy classification

Answer 32

1-5 patches

Question 33

PB leprosy treatment

Answer 33

dapsone and rifampin for 6 months

Question 34

MB leprosy classification

Answer 34

> 5 patches

Question 35

MB leprosy treatment

Answer 35

dapson and rifampin for 6-12 months.

Question 36

Dapsone MOA

Answer 36

PABA antogonist. Similar to sulfonamides inhibits the synthesis of folic acid.

Question 37

Dapsone toxicities

Answer 37

nasal obstruction, hemolysis, GI disturbance.

Question 38

Erythema nodosum leprosum (ENL)

Answer 38

Symptom of leprosy

Question 39

ENL treatment

Answer 39

Thalidomide

Question 40

Thalidomide toxicity

Answer 40

Extremely teratogenic. Most regulated drug in the U.S.