Anti Mycobacterial

Question 1

What is used for prophylaxis to M. Tuberculosis

Answer 1

Isoniazid

Question 2

What are the drugs used in the treatment of M. Tuberculosis

Answer 2

RIPE- Rifampin, Isoniazid, pyrazinamide and ethambutol

Question 3

Which drug is used to treat M. Leprae tuberculoid form

Answer 3

Dapsone and Rifampin

Question 4

Which drug is used to treat M. Leprae lepromatous form

Answer 4

Add clofazimine to phenazine

Question 5

What can phenazine do to the skin over time

Answer 5

Cause skin discolouration pink -> brown/black

Question 6

What is the mechanism of action of Rifamycins

Answer 6

Inhibit DNA dependant RNA polymerases

Question 7

Drugs of rifamycin group

Answer 7

Rifampin

Rid abit in

Question 8

What are Rifamycins used to treat

Answer 8

Used in M. Tuberculosis (Rifampin is first line) and meningococcal prophylaxis

Question 9

Rifamycins use in children

Answer 9

Prophylaxis in contacts of children with H influenza type B

Question 10

Rifamycins adverse effects

Answer 10

Orange blood fluids, CYP 450 inducer (drug interactions) and hepatotoxicity

Question 11

Which of the Rifamycins is favoured with HIV and why

Answer 11

Rifabutin is favoured over Rifampin in HIV infection due to less p450 activation and hepatotoxicity

Question 12

4Rs of rifampin

Answer 12

• RNA polymerase inhibitors
• ramps up p450
• rapid resistance of used alone
• red orange body fluids

Question 13

What is the mechanism of action of Isoniazid (INH)

Answer 13

Decreases the synthesis of mycolic acid

Question 14

Isoniazid is a pro drug what enzyme is needed to get it to its active form

Answer 14

KatG

Question 15

When is Isoniazid used with TB infections

Answer 15

• It is the only drug used as solo prophylaxis

- it is also used as mono therapy for latent TB

Question 16

Isoniazid adverse effects

Answer 16

Hepatotoxicity, Vitamin B6 Deficiency leading to peripheral neuropathy

Question 17

What is administered with isoniazid to prevent B6 deficiency?

Answer 17

Pyridoxine (VitB6)

Question 18

How does isoniazid affect the p450 system

Answer 18

It inhibits P450 which inhibits the metabolism of phenytoin

Question 19

How is resistance developed against isoniazid

Answer 19

Underexpression of KATG gene

Question 20

Mechanism of action of pyrazinamide

Answer 20

Inhibits fatty acid synthesis required for cell membrane function

Question 21

Pyrazinamide Adverse effects

Answer 21

Hyperuricemia (gout) and hepatotoxicity

Question 22

Mechanism of action of ethambutol

Answer 22

Inhibits the enzyme ARABINOSYL transferase and cell wall formation

Question 23

Ethambutol AEs

Answer 23

Optic neuropathy (Red-green colourblindness) EYEthambutol
Hyperuricemia

Question 24

What are the second line drugs of anti mycobacterium

Answer 24

Aminoglycosides
Macrolides
Ethinoamide

Question 25

Which aminoglycoside is used for mycobacterium

Answer 25

Streptomycin

Question 26

Mechanism of action of aminoglycosides

Answer 26

Interferes with 30S component of ribosomes

Question 27

Aminoglycosides AEs

Answer 27

Ototoxicity-vestibular toxicity (vertigo,ataxia,dizziness) Nephrotoxicity(acute tubular necrosis and glomerular toxicity) Cochlear (deafness and tinnitus)

Question 28

Which macrolides are used for mycobacterium

Answer 28

Clarithromycin and azithromycin

Question 29

Macrolides mechanism of action

Answer 29

Interferes with 50S component of ribosomes

Question 30

Macrolides AEs

Answer 30

Prolonged QT interval of ECG, diarrhea, cholestatic jaundice and ototoxicity

Question 31

What is ethionamide

Answer 31

Isoniazid analog

Question 32

Macrolides contraindications

Answer 32

Allergic reactions and hepatic dysfunction

Question 33

Ethionamide adverse effect

Answer 33

Can cause hypothyrodism