Gram positive bacteria: methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant Staphylococcus aureus (MRSA), Streptococcus pneumoniae, Listeria monocytogenes
Gram negative bacteria: Enterobacteriaceae, H. influenzae, other Haemophilus spp., N. gonorrhoeae, N. meningitides, M. catarrhalis, Stenotrophomonas maltophilia, S. maltophilia
Mycobacteria: Mycobacterium tuberculosis, M. fortuitum, M. kansasii, M. intracellulare, M. avium
Atypicals: Legionella pneumophilia, Chlamydia pneumonia, Mycoplasma pneumoniae
Mechanism of Action:
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: 4.5mg/L; Volume of distribution: 2.7L/kg; Table 2
Gastrointestinal: nausea, upper GI discomfort
CNS: headache, insomnia, dizziness; hallucinations, depression, psychotic reactions (rare)
Renal: Interstitial nephritis
Cardiovascular: QTC prolongation, torsades de pointes, arrhythmias
Oral: 400mg tablet
Intravenous: 400mg/250ml IV
Opthalmic: 0.5% solution
Chronic bronchitis: 400 mg PO/IV every 24 hr x 5 days
Community-acquired pneumonia: 400 mg PO/IV every 24 hr x 7-14 days
Conjunctivitis, bacterial: (0.5% ophthalmic solution) 1 drop to affected eye(s) 3 times a day x 7 days
Sinusitis: 400 mg IV or ORALLY every 24 hr for 10 days
Skin/skin structure infection: 400 mg PO/IV every 24 hr x 7 days
Efficacy and safety not established in patients less than 18 years of age
Disease state based dosing:
Renal failure: No dosage adjustment recommended
Hepatic failure: No dosing adjustment recommended
Dosing during Continuous Renal Replacement Therapy
CVVH (Continuous venovenous hemofiltration): 400mg q12h
CVVHD (Continuous venovenous hemodialysis): 400mg IV q12h
CVVHDF (Continuous venovenous hemodiafiltration) 400mg IV q12h
Note: CVVH is mainly for fluid removal alone. Many institutions will employ more CVVHD or CVVHDF which combine dialysis with fluid removal.
Divalent cations: aluminum, magnesium zinc, iron, calcium, antacids, sucralfate – reduced bioavailability of quinolones (can cause therapeutic failure)
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