antitubercular drugs: chapter 46

Question 1

define multidrug resistant tuberculosis (MDR-TB)

Answer 1

Tb that is resistant to isoniazid and rifampin

Question 2

when would a secondary tb drug be used

Answer 2

for tb infections that are resistant to primary drugs

Question 3

what are 4 primary tb drugs

Answer 3

ethambutol, isoniazid, pyrazinamide, rifampin

Question 4

what are 3 secondary tb drugs

Answer 4

amikacin, levofloxacin, moxfloxacin

Question 5

what is the primary drug used to treat tb

Answer 5

isoniazid

Question 6

what are the first 2 steps in the process of starting tb therapy

Answer 6

perform drug susceptibility tests to prevent the development of MDR-TB, begin four drug regimen of isoniazid, rifampin, pyrazinamide, and ethambutol before susceptibility tests are back to reduce the possibility of drug resistance

Question 7

mechanism of action of rifampin

Answer 7

inhibit rna synthesis

Question 8

mechanism of action of isoniazid

Answer 8

inhibit cell wall synthesis

Question 9

mechanism of action of ethambutol

Answer 9

affect lipid synthesis which inhibits protein synthesis

Question 10

mechanism of action of isoniazid

Answer 10

form defective NAD which inhibits life sustaining reactions in the tb organism

Question 11

mechanism of action of pyrazinamide (2)

Answer 11

bacteriostatic or bactericidal depending on the suseptibility of the tb organism and concentration of drug at infection site, inhibit lipid and nucleic acid synthesis

Question 12

what is the major effect of all tb drugs. when will this effect occur

Answer 12

reduction of cough within 2 weeks if the strain is drug sensitive

Question 13

what is the common combination of tb drugs druing pregnancy

Answer 13

isoniazid and ethambutol

Question 14

what drug is used for advanced tb during pregnancy

Answer 14

rifampin

Question 15

2 general contraindications for tb drugs

Answer 15

major kidney or liver dysfunction

Question 16

contraindication for ethambutol

Answer 16

optic neuritis

Question 17

why may tb drugs be used even if there are contraindications. what will be done during therapy when there are contraindications

Answer 17

the risk of the tb progressing outweights the risk of contraindications. use supportive measures to balance the contraindications

Question 18

2 adverse effects of ethambutol

Answer 18

retrobulbar neuritis, blindness

Question 19

4 adverse effects of isoniazid

Answer 19

peripheral neuropathy, hepatotoxicity, hyperglycemia, body fluid discolouration

Question 20

2 adverse effects of pyrazinamide

Answer 20

hepatotoxicity, hyperuricemia

Question 21

2 adverse effects of rifampin

Answer 21

hepatitis

red/orange/brown discolouration of urine, tears, sweat, and sputum

Question 22

which tb drug is considered to be the first line bacteriostatic drug

Answer 22

ethambutol

Question 23

major contraindication for ethambutol in terms of age

Answer 23

contraindication in children younger than 13yrs

Question 24

how is isoniazid metabolized. how may this affect drug therapy

Answer 24

metabolized through the liver through acetylation. caution must be used in those who are slow acetylators due to drug accumulation

Question 25

which tb drug is not commonly used during pregnancy

Answer 25

pyrazinamide

Question 26

which tb drug is effective against other mycobacterium and not just tb

Answer 26

rifampin

Question 27

what is a purified protein derivative injection and is it used for

Answer 27

a diagnostic injection to detect exposure to tb. a positive result is indicated by induration

Question 28

what is a bacillus calmette-guerin injection and why is it given

Answer 28

a vaccine against tb that is given in areas where tb is prevalent to reduce the incidence of active tb and serious cases

Question 29

what must be assessed before administration of isoniazid or rifampin

Answer 29

liver function tests

Question 30

how long does drug therapy for tb typically last for

Answer 30

24 months

Question 31

what is important to stress to patients to increase their chances of successful drug therapy

Answer 31

the drugs must be taken exactly as ordered and at the same time everyday

Question 32

how can you minimize gi upset while taking tb drugs

Answer 32

take with food

Question 33

what 6 symptoms must be immediately reported while on tb therapy

Answer 33

jaundice, nausea, vomiting, dark urine, anorexia, vision changes

Question 34

why is pyridoxine given alongside isonazid

Answer 34

to prevent peripheral neuropathies and numbness, tingling, or burning of extremities

Question 35

a female patient is about to start rifampin and asks if there will have to be any changes to her oral contraceptives. what information will the nurse provide

Answer 35

the nurse will tell the patient that oral contraceptives can be ineffective while on rifampin and other birth control methods should be explored

Question 36

what teaching should be provided to a patient who wears contact lenses and is taking rifampin

Answer 36

contact lenses will be permanently stained

Question 37

a patient asks the nurse how the doctors will know if her condition is improving. what will the nurse tell the patient

Answer 37

a therapeutic response to the drug therapy will be seen through a decrease in symptoms, improved clinical status, and improved lab and chest x-ray findings