33.quinolones

Question 1

definition of Quinolones

Answer 1

synthetic antimicrobial agents related to 4-quinolone

Question 2

Quinolones can be administered how?

Answer 2

1.orally
2.topically
3. i.v
4. eye drops

Question 3

how many are the classes of quinolones

Answer 3

1st generation - non fluorinated
2,3,4th - fluoroquinolones

Question 4

name drugs of 1st generation quinolones

Answer 4

Nalidixic acid - tab.500mg

Question 5

name drugs of the 2nd class of fluoroquinones

Answer 5

1.ciprofloxacin tab.500mg
2. norfloxacin tab.400mg

Question 6

name drugs of 3rd class of fluoroquinolones

Answer 6

levofloxacin tab.500mg/24hrs

Question 7

name drugs in 4th class of fluoroquinolones

Answer 7

moxifloxacin (avelox) tab.400mg

Question 8

SoA of non-fluorinated quinolones

Answer 8

1.narrow - gram negative
2.bacteriostatic

Question 9

when are non-fluorinated quinolones used?

Answer 9

non-complicated UTI (not against P.aeruginosa) - but resistance is developed quickly

Question 10

when are non-fluorinated quinolones contraindicated?

Answer 10

in renal failure (clearance less than 50ml/min)

Question 11

Absorption of Quinolones

Answer 11

well absorbed when given orally

Question 12

which quinolones has the least absorption?
what is it used for?

Answer 12

norfloxacin - for GIT infections

Question 13

what can reduce the absorption of quinolones?

Answer 13

when they are taken with supplements that contain aluminium or magnesium antacids,
iron, zinc, calcium

Question 14

volume of distribution of quinolones?

Answer 14

distribute well into all tissues and body fluids

Question 15

where do quinolones accumulate?
how do they distribute?

Answer 15

1.in macrophages and polymorphonuclear leucocytes - active agsinst intracellular organisms
2.can cross the BBB and placental barrier
3.have low PBB (10-40%)

Question 16

which quinolone in an enzyme inhibitor (inhibiting liver drug metabolising enzymes)

Answer 16

ciprofloxacin

Question 17

excretion of quinolones

Answer 17

1. renal - dosage adjustment in renal failure
2. moxifloxacin by liver

Question 18

MoA of fluoroquinolones

Answer 18

1. inhibit DNA gyrase (bacterial topoisomerase II)
   resulting in relaxation of supercoiled DNA, promoting DNA strand breakage
   —topoisomerase II inhibition is seen in Gram -

2.inhibit topoisomerase 4 and interfere with separation of newly replicated DNA during cell division (gram +)

-BACTERICIDAL

Question 19

SoA of fluoroquinolones

Answer 19

BROAD
1.gram - : e.coli, p.aeruginosa, h.influenzae
2.gram + : strepto
3.atypical mo: legionella, chlamydia
4.m.TB

Question 20

Moxifloxacin SoA

Answer 20

active against ANaerobes

Question 21

2nd generation quinolones are active against?

Answer 21

gram negative

Question 22

3th and 4th generation are used against?

Answer 22

gram positive

Question 23

levofloxacin and moxifloxacin are referred to as …. fluoroquinolones

Answer 23

respiratory

Question 24

adverse drug reactions of quinolones

Answer 24

1.disbacteriosis
2.GI symptoms
3.photosensitivity - advise to wear suncream
4.articular cartilage erosion (arthropathy) - avoid in pregnancy/lactation/children under 18
5.increased risk of tendinitis
6.neurotoxicity: headache, dizziness, seizures
7.cardiotoxicity: prolong QT (not taken by people on meds that prolong it)
8.hemolytic anemia in patients with G6PD deficiency

Question 25

fluoroquinolones are used for?

Answer 25

1.respiratory infections
2.GI
3.ophthalmic
4.UTI
5.prostatic
6.bone/joint diseases

Question 26

contraindication of fluoroquinolones

Answer 26

1.pregnancy and lactation
2.renal failure
3.epilepsy
4.hypersensitivity reaction

Question 27

drug interactions of fluoroquinolones

Answer 27

1.ciprofloxacin can increase serum levels of theophylline (increased risk of seizures) by inhibiting its metabolism
2.quinolones may increase the level of warfarin + caffeine
3. have synergic effect with b-lactam AB but have to be applied separately