Quinolones, Antifolates, Metronidazole

Question 1

MOA of fluoroquinolone

Answer 1

inhibit DBA gyrase in gram neg and topoisomerase IV in gram positive

Question 2

Name 3 Fluoroquinolones

Answer 2

1. Ciprofloxacin
2. Levofloxacin
3. Moxifloxacin

Question 3

How is fluoroquinolones administered?

Answer 3

Oral, best on empty stomach (not with calcium or cation, sep by 2h b4 or 6h aft)

Question 4

Distribution of fluoroquinolone

Answer 4

High in bones, urine except moxifloxacin

Question 5

Clearance of fluoroquinolone

Answer 5

Renal except moxifloxacin hep meta

Question 6

Can fluoroquinolone be used against Pseudomonas?

Answer 6

Yes

Question 7

Can ciprofloxacin be used agaimst MRSA?

Answer 7

No

Question 8

ADR of fluoroquinolones

Answer 8

1. Gi NVD
2. Aortis dissections
3. CDAD (ESP Cipro)
4. headache, dizziness
5. Phototoxicity
6. Tendon rupture
7. Joint problems (not for <18)
8. QTc prolongation (3rd gen)
9. Peripheral neuropathy
10. Dysglycaemia in DM pts

Question 9

CI for fluoroquinolones

Answer 9

Preg, myasthenia, G6PD def

Question 10

Name 3 antifolates

Answer 10

1. Sulfonamide
2. Trimethoprim
3. Cotrimoxazole

Question 11

MOA of antifolate

Answer 11

Blocks biosynthesis pathway for tetrahydrofolate

Question 12

MOA os sulfonamide

Answer 12

Inhibit dihydropteriate synthase competitively to prevebt synthesis of dihydropteroic acid, precusor of folate, b9

Question 13

ADR of sulfonamides

Answer 13

1. Crystalluria - prevent by hydration and allalising urine, red cocn of drug
2. Hypersensitivity sulfa allergies
3. Hematopoietic disturbances
4. Kernicterus in newborns

Question 14

MOA of trimethoprim

Answer 14

Inhibits bacterial dihydroflate reductase preventing rduction if dihydrofolic acid to active form

Question 15

ADR of trimethoprim

Answer 15

Folic acid deficiency (can take with folinic acid)

Question 16

What does cotrimoxazole consist of?

Answer 16

1 Trimethoprim: 5 sulfamethoxazole