Quinolone
Gram-positive: methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant Staphylococcus aureus (MRSA), Streptococcus pneumoniae, Listeria monocytogenes
Gram-negative: Enterobacteriaceae, H. influenzae, other Haemophilus spp., N. gonorrhoeae, N. meningitides, M. catarrhalis, Stenotrophomonas maltophilia, S. maltophilia
Mycobacteria: Mycobacterium tuberculosis, M. fortuitum
Atypicals: Legionella pneumophilia, Chlamydia pneumonia, Mycoplasma pneumoniae
Inhibition of topoisomerase (DNA gyrase) enzymes, which inhibits relaxation of supercoiled DNA and promotes breakage of double stranded DNA.
Fluoroquinolones produce both concentration-dependent (peak:MIC), and a combination of concentration and time-dependent killing (AUC:MIC).
400mg dose; Cmax: 3.4mg/L; Volume of distribution: 1.7 L/kg; Table 2 & Table 3
Divalent cations: aluminum, magnesium zinc, iron, calcium, antacids, sucralfate – reduced bioavailability of quinolones (can cause therapeutic failure)
Tablets: 200mg, 400mg tablets
IV: 2mg/ml for IV administration
Opthalmic: 0.3% solution
Community acquired pneumonia: 400mg IV/PO x 7-14 days
Acute sinusitis: 400mg IV/PO x 10 days
Conjunctivitis: 1 drop into affected eye q2h while awake up to 8 times per day x 2 days, then 1 drop up to 4 times/day for 4 more days.
Acute exacerbation of chronic bronchitis: 400mg IV/PO x 5 days
Uncomplicated UTI: 400mg IV/PO x 1 dose / 200mg IV/PO q24h x 3 days
Complicated UTI/Pyelonephritis: 400mg IV/PO x 7-10 days
Uncomplicated gonococcal infections: 400mg IV/PO x 1 dose
Uncomplicated skin/skin structure: 400mg IV/PO x 7-10 days
Conjunctivitis: 1 drop into affected eye q2h while awake up to 8 times per day x 2 days, then 1 drop up to 4 times/day for 4 more days.
Renal failure: CrCl < 40 mL/min: 400mg x 1, then 200mg q 24 hours
Hemodialysis: 400mg x 1, then 200mg q 24 hours after dialysis
Peritoneal dialysis: 400mg x 1, then 200mg q 24 hours
Hepatic failure: No dosing changes recommended at this time.
Precautions:
Anticoagulants: Warfarin (prolonged warfarin half-life)
Divalent cations: aluminum, magnesium zinc, iron, calcium, antacids, sucralfate – reduced bioavailability of quinolones (can cause therapeutic failure)
Theophylline, caffeine, xanthines: clearance of these is inhibited with fluoroquinolones
Category C: Risk unknown. Human studies inadequate.
Therapeutic: Culture and sensitivities, signs and symptoms of infection
Toxic: Urinalysis, BUN, SCr, AST and ALT, Physicial examination: encephalopathic changes