ANTIBIOTIC:
QUINOLONE

Quinolone

PO and IV, topical eye drops and ointment

Bacteriocidal antimicrobials that block DNA replication by blocking tropoisomerase enzymes, which are essential for the supercoiling, replication and separation of circular bacterial DNA

Broad spectrum
Active against both gram positive and gram negative bacteria

particularly effective against
GNB (E.Coli, H.influenza, Klebsiella, Legionella, Moraxella, Proteus, and Pseudomonas)
Less effective against Gram-positive bacteria (such as MSSA, Strep pneumoniae, and Enterococcus faecalis) than newer fluoroquinolones

Alteration in target enzyme – changes to the DNA binding surface of DNA supergyrase infers resistance
Alteration in drug entry – altered expression of outer membrane porin proteins that form channels for passive diffusion of ciprofloxacin
Increase in efflux of drug – expression of nonspecific energy dependent efflux pumps which remove drug

1. CNS Toxicity- GABA antagonists and may precipitate seizures in epileptic patients, particularly in presence of NSAIDs
2. Tendonitis and tendon rupture
3. QT prolongation- Low risk of Torsade’s in absence of other predisposing factors
4. Hemolysis in G6PD
5. Photosensitivity
6. Arthralgias and cartilage toxicity (generally avoided in children)
7. Dysglycaemia (hyper and hypoglycaemia)

Good oral absorption (80%)

Undergoes first pass

Coadministration of calcium or magnesium reduces absorption

High CSF and tissue penetration

30% PB

Vd 2-3L/kg

Little hepatic metabolism

Active tubular secretion

T1/2= 3 hours (renal dose adjustment required)

Level 3

Level 1