Anti-Mycobacterials

Question 1

Which drugs are considered “Antimycobacterials”? These drugs are also considered “first lines”?

Answer 1

Isoniazid    (INH)
Rifampin
Ethambutol
Pyrazinamide 
Streptomycin

Question 2

What stain is specific to Mycobacterium?

Answer 2

Acid Fast

Question 3

What are the 2 divisions of treatment for Mycobacterium?

Answer 3

1. Chemoprophylaxis

2. Active Disease

Question 4

What is Chemoprophylaxis?

Answer 4

Giving a drug to prevent the development of clinically active disease in people already infected with the organism

Question 5

In treating mycobacterium tuberculosis, how many drugs and what type (cidal or static) should the person be taking?

Answer 5

2 drugs concurrently

CIDAL

Question 6

Which drug is almost always the initial drug?

Answer 6

INH (Isoniazid)

Question 7

Which combination of drugs has good efficacy to treat TB?

Answer 7

INH + Rifampin

Question 8

How long should the person be on the treatment?

Answer 8

for at least 3-6 mo after sputum becomes negative to sterilize the lesions and prevent relapse

Question 9

What triple therapy should be given if the treatment is to last 2 mo?

Answer 9

INH + rifampin + pyrazinamide for two months

plus either ethambutol or streptomycin

Question 10

After the 2 mo treatment for TB, what therapy follows?

Answer 10

INH + rifampin for four months

Question 11

What other 9 mo alternative to treat TB is there?

Answer 11

INH + rifampin is also effective

Question 12

What treatment should be administered if the patient is resistant to INH and Rifampin?

Answer 12

treat with 3 or more drugs to which the organism is susceptible & continue for 12-24 months after the culture becomes negative

Question 13

What is DOT and who would benefit from it?

Answer 13

Intermittent therapy & Directed observed therapy

For patients who can not be relied upon to take daily medication, but who can be followed as OP in a clinic

Question 14

What does the DOT therapy consist of?

Answer 14

Consists of daily therapy for 2 weeks (INH, rifampin, pyrazinamide, & streptomycin) followed by therapy 2 times a week for 6 weeks, followed by INH + rifampin twice weekly for 18 weeks

Question 15

Is Isoniazid CIDAL or STATIC?

Answer 15

CIDAL

Question 16

What is Isoniazid active against?

Answer 16

against actively growing bacilli, both extracellular & intracellular

Question 17

What is the MOA of Isoniazid ?

Answer 17

Interferes with biosynthesis of cell wall mycolic acids

Question 18

How does TB gain resistance of Isoniazid and Rifampin?

Answer 18

due to drug accumulation or alteration of target enzyme

Question 19

How is Isoniazid administered?

Answer 19

Readily absorbed orally or parenterally

Question 20

Does Isoniazid get into the CSF?

Answer 20

Yes and caseous lesions

Question 21

What is the primary metabolic route of Isoniazid?

Answer 21

Acetylation

Question 22

How is INH excreted ?

Answer 22

75-95% of the dose is excreted in the urine in 24 hrs

also excreted in the saliva, sputum, and breast milk

Question 23

What are the adv eff of INH?

Answer 23

1. Peripheral neuritis
2. Hepatotoxicity
3. Potential for seizures
4. Inhibits metabolism of phenytoin
5. Hypersensitivity – rash; fever

Question 24

A patient is experiencing peripheral neuritis? What caused the agent and what should be done to alleviate the patient?

Answer 24

1. INH

2. Pyridoxine

Question 25

What is Rifampin?

Answer 25

Complex macrocyclic antibiotic

Question 26

Is Rifampin CIDAL or STATIC?

Answer 26

CIDAL

Question 27

What bacteria is Rifampin active against?

Answer 27

against extracellular cavitary bacilli & organisms in closed lesions (macrophages & caseous lesions) - M. tuberculosis, M. leprae, atypical mycobacteria - Prophylaxis for exposure to meningococcal or H. influenzae meningitis

Question 28

What is the MOA of Rifampin?

Answer 28

Inhibits bacterial DNA-dependent RNA polymerase

Question 29

How is Rifampin administered?

Answer 29

Well absorbed from orally

Question 30

Does Rifampin get into the brain?

Answer 30

Yes

Question 31

This drug has a progressively shortened half-life owing it to it's own ability to induce hepatic enzymes that accelerate its own metabolism. What is the drug?

Answer 31

Rifampin

Question 32

This drug is rapidly eliminated via bile, followed by enterohepatic recirculation that goes to the feces and urine. What drug is this?

Answer 32

Rifampin

Question 33

What are some adverse rxs of Rifampin?

Answer 33

Hypersensitivity GI: epigastric distress, N/V, cramps, diarrhea Fever Hepatotoxicity leading to: jaundice

Question 34

A patient is complaining of orange-red colored saliva, tears, and urine--even their sweat is orange. And have noticed a discoloration of their contact lens. What is the causative agent?

Answer 34

Rifampin

Question 35

What drugs should a patient avoid if they are taking Rifampin? and why?

Answer 35

``` Rifampin is a potent inducer of P 450 : increases metabolism of other drugs Oral contraceptives Warfarin Prednisone Digoxin Quinidine Ketoconazole Propranolol Clofibrate Sulfonylureas ```

Question 36

What is the MOA of Pyrazinamide?

Answer 36

Unknown

Question 37

How is Pyrazinamide used clinically?

Answer 37

INH and Rifampin

Question 38

Is Pyrazinamide CIDAL or STATIC?

Answer 38

CIDAL to actively dividing bugs

Question 39

How is Pyrazinamide administered?

Answer 39

absorbed well orally

Question 40

Does Pyrazinamide get into the CSF?

Answer 40

Yes

Question 41

What are some adverse effects of Pyrazinamide?

Answer 41

Hepatotoxic Hyperuricemic = Gout Occasional GI effects

Question 42

What is the MOA of Ethambutol?

Answer 42

Unknown

Question 43

Is Ethambutol CIDAL or STATIC?

Answer 43

STATIC

Question 44

How is Ethambutol administered?

Answer 44

Orally

Question 45

What are some adverse effects of Ethambutol?

Answer 45

OPTIC NEURITIS: bi- or unilateral – loss red/green discrimination examine visual acuity periodically Urate retention & gouty attacks