Quinolones and Macrolides

Question 1

What are quinolones?

Answer 1

They are derivatives of nalidixic acid which is a 1,8-naphthyridine antibacterial agent.

Question 2

Why are fluoroquinolones called that?

Answer 2

Presence of one or more fluorine

Question 3

Quinolones are mainly active against?

Answer 3

Quinolones are mainly active against gram-negative aerobic bacteria e.g P. aeruginosa, E.coli. but have some activity against gram-positive pathogens as their spectrum expands.

Question 4

What is the MOA of quinolones?

Answer 4

They inhibit the enzyme topoisomerase 2 (DNA gyrase) leading to the impaired transcription of DNA to RNA and preventing protein synthesis.

Question 4

Quinolones are used to treat?

Answer 4

1. Genitourinary infections
2. Upper and lower respiratory tract infections
3. Skin and soft tissue infections

Question 5

T or F. Quinolones are bacteriostatic at low concentrations and bactericidal at high concentrations.

Answer 5

True

Question 6

What are the characteristics of the first generation of quinolones.

Answer 6

They have basic spectrum and minimum serum levels

Question 6

Give examples of the first generation of quinolones.

Answer 6

Nalidixic acid, Cinoxacin, Oxolinic acid

Question 7

What are the characteristics of the second generation of quinolones.

Answer 7

Increased gram negative and systemic activity

Question 8

Give examples of the second generation of quinolones.

Answer 8

Ciprofloxacin, Norfloxacin, Enoxacin, Ofloxacin, Lomefloxacin, Perfloxacin

Question 9

Give examples of the third generation of quinolones.

Answer 9

Levofloxacin, Sparfloxacin, Moxifloxacin

Question 9

What are the characteristics of the third generation of quinolones.

Answer 9

Expanded gram positive activity

Question 10

What are the characteristics of the fourth generation of quinolones.

Answer 10

Significant activity against anaerobes in addition to gram positive activity

Question 11

Give examples of the fourth generation of quinolones.

Answer 11

Trovafloxacin (Trovan)

Question 12

What are the adverse effects of quinolones?

Answer 12

1. Erosion of cartilage in young animals hence contraindicated in people below 18 and pregnant and nursing mothers
2. GIT disturbance, hepatotoxicity, cardiotoxicity
3. CNS symptoms
4. Disabling effects of fluoroquinolones on tendons, muscles and joints

Question 13

What drugs to quinolones interact with?

Answer 13

1. Quinolones should not be co-administered with antacids or drugs containing Al, Mg, Zn, Ca, Fe because they form stable complexes with metal ions
2. Not to be co-administered with theophylline and caffeine as they inhibit their metabolic clearance and increase their concentration to toxic levels.

Question 14

What is the IUPAC name of ciprofloxacin (ciprotab)

Answer 14

1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-3-quinoline-carboxylic acid