Quinolones

Question 1

Source and chemistry

Answer 1

synthetic.
quinolones are fluorinated except Nalidixic acid and Cinoxacin

Question 2

Absorption

Answer 2

well absorbed except in the presence of antacids containing Al3+ and Mg2+.

Question 3

Distribution

Answer 3

Poor passage across BBB and Pass placental barrier.

Question 4

Metabolism

Answer 4

liver EXCEPT Ofloxacin.

Question 5

Excretion:

Answer 5

1. Urine
   2.biliary

Question 6

Action on bacteria

Answer 6

Bactericidal.

Question 7

Mechanism of action

Answer 7

They inhibit DNA synthesis by inhibition of DNA gyrase (Topoisomerase II) which is responsible for supercoiling of bacterial DNA.

Question 8

1st generation Quinolones:

Answer 8

Nalidixic acid).

Question 9

2nd generation Quinolone

Answer 9

Cinoxacin

Question 10

3rd generation Quinolones

Answer 10

Fluoroquinolones):
1. Norfloxacin
2. Ciprofloxacin
3. Ofloxacin

Question 11

New fluoroquinolones

Answer 11

1. Levofloxacin
2. Trovafloxacin
3. Cinfloxacin

Question 12

Adverse effects:

Answer 12

1.Reversible arthropathy (damage of growing articular cartilage of bones), tendonitis, and joint swelling.
2. Allergy: skin rash and photosensitivity
3. Nephrotoxic & Crystalluria

Question 13

Contraindications

Answer 13

1) Pregnancy and lactation.
2) Pre-pubertal children.
3) Allergy.
4) Epilepsy