Ant-Mycobacterial Drugs

Question 1

What are mycobacteria?

Answer 1

Slender, curved rods
Cell walls are complex

Question 2

What are the 2 broad groups of mycobacteria?

Answer 2

Mycobacterium tuberculosis species
Nontuberculous species

Question 3

What are 3 mycobacterial diseases?

Answer 3

T.B.
Leprosy
Lung infections in AIDS and CF patients

Question 4

What is unique to mycobacteria structure?

Answer 4

Thick mycolate-rich outer covering -> efficient barrier

Question 5

What is MDR-TB?

Answer 5

Multi drug resistant TB that is resistant to at least isoniazid and rifampicin

Question 6

What is XDR-TB?

Answer 6

Extended drug resistance

Question 7

What are the first line anti-TB drugs?

Answer 7

Isoniazid
Rifampicin

Question 8

What are the 2nd line anti-TB drugs?

Answer 8

Aminoglycosides
Fluoroquinolone

Question 9

How long is compound drug therapy for TB?

Answer 9

6 months

Question 10

When is Isoniazid bactericidal?

Answer 10

For actively growing tubercle bacilli

Question 11

What is Isoniazid’s MoA?

Answer 11

Inhibits synthesis of mycolic acids
Combines with an enzyme leading to disorganization of metabolism

Question 12

How is resistance to Isoniazid developed?

Answer 12

Absence of catalase peroxidase
Reduced penetration
Over-expression of carrier proteins

Question 13

How is isoniazid administered?

Answer 13

orally

Question 14

How is isoniazid distributed?

Answer 14

Widely - reaches BBB

Question 15

How is isoniazid metabolised?

Answer 15

Acetylation

Question 16

How is isoniazid excreted?

Answer 16

Renal

Question 17

What are s/e of Isoniazid?

Answer 17

Allergic skin reactions
Memory loss
hepatotoxicity
seizures

Question 18

Is Rifampicin bactericidal for mycobacteria?

Answer 18

yes

Question 19

What is the MoA of Rifampicin?

Answer 19

Binds to B subunit of DNA
Binds to RNA polymerase -> conformational change

Question 20

How is resistance to rifampicin acquired?

Answer 20

RNA polymerase mutations
Mutations in rpoB
Ribosylation - degradative mechanism

Question 21

What are side effects of Rifampicin?

Answer 21

Nephritis
Turns urine, sweat, tears orange
Cholestatic jaundice
Induction of cytochrome P450 -increased drug elimation

Question 22

What are Rifampicin’s clinical uses?

Answer 22

Leprosy
Prophylaxis for contacts of TB

Question 23

What is an example of an aminoglycoside drug that treats TB?

Answer 23

Capreomycin

Question 24

What is capreomycin’s MoA?

Answer 24

Peptide antibiotic-protein synthesis inhibitor

Question 25

How is capreomycin administered?

Answer 25

Intra muscularly

Question 26

What are s/e of capreomycin?

Answer 26

Nephrotoxicity Ototoxicity

Question 27

What is Cycloserine's MoA?

Answer 27

Inhibitor of cell wall synthesis

Question 28

How is Cycloserine administered?

Answer 28

Orally

Question 29

What are s/e of Cycloserine?

Answer 29

Peripheral neuropathy CNS disturbance

Question 30

What is Amikacin?

Answer 30

Aminoglycoside antibiotic

Question 31

What is Amikacin's MoA?

Answer 31

Protein synthesis inhibitor

Question 32

What is Amikacin effective against?

Answer 32

Atypical mycobacteria Role in MDRs

Question 33

How is Amikacin adminsitered?

Answer 33

I.V

Question 34

What are the 2 types of Leprosy?

Answer 34

Tuberculoid leprosy Lepromatous Leprosy

Question 35

What drugs treat tuberculoid leprosy?

Answer 35

Dapsone and rifam[icin X 6/12

Question 36

What is tuberculoid leprosy characterized by?

Answer 36

Tumours in skin and cutaneous nerves

Question 37

What drugs treat Lepromatous leprosy?

Answer 37

Dapsone, rifampicin and clofazimine X 2 yrs

Question 38

how is lepromatous leprosy characterized by?

Answer 38

Lesions that spread over much of the body affecting many systems

Question 39

What is Dapsone MoA?

Answer 39

Inhibits folate synthesis

Question 40

How is Dapsone administered?

Answer 40

Orally

Question 41

How is Dapsone distributed?

Answer 41

widely lasts long

Question 42

How is Dapsone excreted?

Answer 42

renally

Question 43

What is a s/e of dapsone?

Answer 43

Erythema Nodosum leprosum

Question 44

What are Dapsone clinical uses?

Answer 44

Leprosy PCP in AIDS patients blistering skin rash

Question 45

What is Clofazimine MoA?

Answer 45

Inhibition of DNA synthesis Anti-inflammatory action

Question 46

How is Clofazmine administered?

Answer 46

Orally

Question 47

What are s/e of Clofazmine?

Answer 47

Red discolouration os skin and urine nausea headache

Question 48

What is Mycobacterium Avium complex?

Answer 48

Causes pneumonia in immunisuppressed patients eg HIV

Question 49

How is MAC treated?

Answer 49

Macrolides Rifampicin