Broad spectrum Cidal agents used most for G- and some G+

G-: inhibit DNA gyrase

G+: inhibit topoisomerase IV

Cirpofloxacin (Cipro)

2nd Generation of FQ

Best FQ for G-

ophthalmic (ciloxan), otic (cirpohcotic)

Drug Interactions:

-decreases clearance of theophylline --> increases concentration --> toxicity

-Cipro inhibits CYP3A4 & CYP1A2 --> increases levels of methadone and tizanidine--> possible respiratory distress (methadone) or sedation, hypotension, hallucinations (tizanidine)

2nd Gen FQ

least active, low system levels

UTI only

2nd Gen FQ

Oral is generic

ocuflox = ophthalmic, otic is also available

3rd Gen FQ

opthalmic solution only

3rd Gen Respiratory FQ

nothing stands out about this drug but we still need to know it

3rd Gen Respiratory FQ

Active isomer of ofloxacin.

Avoid if there are conduction anomalies (increases the risk of a prolonged Q-T interval in eledry; Torsades de pointes)

FDA Warning: Risk of acute hepatitis and fatal events

3rd Gen Respiratory FQ

Metabolized primarily in the liver. Caution for hepatic disease patients.

Can prolong Q-T interval in healthy patients.

opthalmic = Vigamox

4th Gen FQ

Approved for bacterial conjunctivitis due to susceptible organisms

Side Effects of all Fluroquinolones

• Phototoxicity - burning, redness, swelling, blisters, rash, itch
• Arthropathy - damages growing cartilage. Do not use in prepubertal children or pregnant women
• Tendon Rupture - Black Box warning; risk greater for people over 65 or taking steroids (may take a few months to show up)
• Diabetics only - can increase or decrease blood sugar if taken with insulin or an oral hypoglycemic
• CNS Stimulation - convulsion, anxiety
• Naseau, Vommiting, Diarrhea - major cause of C. difficile-induced diarrhea & pseudomembranous colitis. C. difficile survives as spores until antibiotics are stopped. It then grows w/o competition. Produces 2 exotoxins that cause intestinal fluid secretions, mucosal injury, inflammation, bloody diarrhea, & disruption of tight junctions. A placque that looks like a membrane forms around the colon mucosa (pseudomembrane)

Avoid use with antacids and Fe supplements. (Chelate with mono & divalent cations thus decreasing absorption of antiobiotic)