CPRS 82: Drugs to Treat Tuberculosis and Influenza

Question 1

How long does it take to undergo a tuberculin skin test

Answer 1

48-72 hours

Question 2

What are the 3 categories for Diagnosis of TB in the Tuberculin Test
Category 1:
Category 2:
Category 3:

Answer 2

Category 1: Immuno-compromised
Category 2: Someone who have contact with TB
Category 3: People with normal immune system

Question 3

How large is the tuberculin test thing for Categories 1, 2, and 3?

Tested Positive

Answer 3

Category 1: 5-9mm
Category 2: 10-14mm
Category 3: 15mm or more

Question 4

What are the diagnosis of TB

Answer 4

Positive Skin Test
Abnormal Chest Radiograph
Positive sputum smear or culture

Question 5

Which two drugs are the most effective among the primary agents to treat TB

Answer 5

Rifampicin

Isoniazid

Question 6

Secondary TB drugs are more _____ and less _____ than primary TB drugs

Answer 6

more toxic

less effective

Question 7

Why will people be administered secondary TB drugs

Answer 7

Unable to tolerate primary drugs

Treat TB infections resistant to primary drugs

Question 8

Name the Mechanism of Isoniazid (INH)
Overall:
Detailed steps:

Answer 8

Overall: Inhibit cell wall synthesis
Details:
1. Isoniazid is a prodrug, converted to active form by catalase peroxidase
2. INH inhibits InhA, which is responsible for FAS-II synthesis, which synthesizes LONG-CHAIN mycolic acids, which is a key component of cell wall of mycobacteria

Question 9

Side effects to Isoniazid?

Answer 9

Liver injury: Hepatitis

Peripheral Neuropathy

Question 10

How can liver injury be indicated

Answer 10

Elevated ALT and AST (Enzymes released into circulation if there is liver damage)

Question 11

How can peripheral neuropathy be treated

Answer 11

Pyridoxine (vitamin B6)

Question 12

Name the Mechanism of Rifampicin
Overall:
Detailed steps:

Answer 12

Overall: Inhibit synthesis of RNA, producing defective proteins
Details:
1. Binds to Beta-subunit of RNA polymerase
2. Inhibits transcription of mRNA and damage protein synthesis

Question 13

Name an adverse effect of Rifampicin

Answer 13

Harmless red-orange discolourization of secretions

Question 14

Name the Mechanism of Ethambutol
Overall:
Detailed steps:

Answer 14

Overall: Inhibit Cell Wall Synthesis
Details:
1. Inhibits EmbB action
2. EmbB is involved in arabinogalactan synthesis, which is a component of cell wall in mycobacterium

Question 15

Name an adverse effect of Ethambutol

Answer 15

Optic Neuritis- Demyelinating disorder of the optic nerve, reduces the acuity to distinguish red from green

Question 16

Name the Mechanism of Pyrazinamide
Overall:
Detailed steps:

Answer 16

Overall: Inhibit Cell Wall Synthesis
Details:
1. Pyrazinamide (prodrug) broken down to pyrazinoic acid (pyrazinamidase)
2. Pyrazinoic acid inhibits FAS-I, which is involved in synthesis in short chain mycolic acids

Question 17

Pyrazinamide has weak ___________ activity but strong _________ activity

Answer 17

Pyrazinamide has weak extracellular activity but strong intracellular bactericidal activity

Question 18

Name the Mechanism of Streptomycin
Overall:
Detailed steps:

Answer 18

Overall: Interferes with mRNA translation
Details:
1. Streptomycin binds to ribosomal protein that is component of 30s subunit of ribosomal complex
2. Facilitates codon misreading and disrupts proper protein synthesis

Question 19

Name an adverse effect related to Streptomycin

Answer 19

Affects hearing

Question 20

Through which method can Streptomycin can only be administered?

Answer 20

Intramuscular injection

Question 21

Streptomycin can act against extracellular/ intracellular organisms?

Answer 21

Extracellular