Pharm - TB

Question 1

MOA isoniazid

Answer 1

Inhibits mycolic acid synthesis

Question 2

AE isoniazid

Answer 2

1. Hepatitis
2. Inhibit CYP450
3. Peripheral neuropathy

Question 3

Interactions INH

Answer 3

1. Aluminum antacids decrease absorption
2. Inhibits cortisol metabolism
3. GC’s decrease INH blood levels

Question 4

What supplementation should to be given to pt on INH?

Answer 4

B6/pyridoxine = competes with pyridoxal phosphate, causing peripheral neuropathy

Question 5

MOA rifampin

Answer 5

Inhibits DNA-dep RNA polymerase by binding Beta-subunit

Question 6

AE rifampin

Answer 6

1. Rust colored bodily fluids

2. CYP450 induction

Question 7

Interactions rifampin

Answer 7

Probenecid increases rifampin levels; important since EMB and PZA can cause hyperuricemia so TB pt likely to need gout meds

Question 8

MOA ethambutol

Answer 8

Inhibits arabinosyl transferase = inhibits cell wall synthesis

Question 9

AE EMB

Answer 9

1. Optic neuritis

2. Hyperuricemia

Question 10

Interactions EMB

Answer 10

Aluminum antacids decrease EMB absorption

Question 11

MOA pyrazinamide

Answer 11

Converted to pyrazinoic acid, decreasing pH below what is favorable for growth of TB

Question 12

AE pyrazinamide

Answer 12

1. Hepatitis
2. Hyperuricemia
3. Myaglia

Question 13

MOA cycloserine

Answer 13

Analog of D-ala; inhibits L-ala racemase and D-ala synthetase

Question 14

AE cycloserine

Answer 14

1. Suicidal ideations
2. Seizures
3. Depression

Question 15

CI cycloserine

Answer 15

Epilepsy

Question 16

MOA ethionamide

Answer 16

Analog of INH; inhibits protein synthesis

Question 17

AE ethionamide

Answer 17

1. GI
2. Neuro
3. Hepatotoxicity

Question 18

What supplementation should be given with ethionamide?

Answer 18

B6 - remember it’s an INH analog

Question 19

MOA capreomycin

Answer 19

Unknown

Question 20

AE capreomycin

Answer 20

1. Nephrotoxicity

2. Ototoxicity

Question 21

Which TB drug can be used alone?

Answer 21

Ethionamide

Question 22

Which TB drugs require concomitant B6?

Answer 22

INH and ethionamide

Question 23

Which TB drugs cross CSF and placenta?

Answer 23

INH, EMB, PZA, cycloserine

Question 24

Which TB drugs should you avoid with antacids?

Answer 24

INH, EMB

Question 25

Which TB drugs are both bacteriocidal and bacteriostatic?

Answer 25

INH PZA Cycloserine Ethionamide

Question 26

Only bacteriocidal?

Answer 26

RIF

Question 27

Only bacteriostatic?

Answer 27

EMB | Capreomycin

Question 28

Rifampin vs. rifapentine

Answer 28

Rifapentine has longer T1/2 = once weekly dosing | Also less induction of CYP450

Question 29

Rifampin v. rifabutin

Answer 29

Rifabutin has least induction of CYP of the rafamycins

Question 30

Which TB drug is N-acetylated?

Answer 30

INH

Question 31

Resistance to RIF develops because of:

Answer 31

Change in beta-subunit of DNA-dep RNA polymerase

Question 32

Which TB drug necessitates back up birth control?

Answer 32

RIF (remember it INDUCES CYP450 = lower OC blood levels)

Question 33

Active TB must be treated for a minimum of:

Answer 33

24 weeks

Question 34

Latent vs. active TB tx

Answer 34

``` Latent = 3 months of INH + rifapentine Active = 24 weeks of RIPE or RIPS ```

Question 35

What is CI for tx of LTBI?

Answer 35

RIF + PZA due to liver toxicity