Gemifloxacin  (PDF Version)


Antibiotic Class:



Antimicrobial Spectrum:

Gram-positive:  methicillin-susceptible Staphylococcus aureus (MSSA) (highest quinolone activity vs. MSSA), methicillin-resistant Staphylococcus aureus (MRSA), Streptococcus pneumoniae, Enterococcus faecalis, Listeria monocytogenes

Gram-negative:  Enterobacteriaceae, H. influenzae, other Haemophilus spp., N. gonorrhoeae, N. meningitides, M. catarrhalis, Stenotrophomonas maltophilia

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).



320mg dose; Cmax: 1.6mg/ml; Volume of distribution: 4.18; Table 2  


Adverse Effects:

Gastrointestinal: nausea, upper GI discomfort

CNS:  headache, insomnia, dizziness; hallucinations, depression, psychotic reactions (rare)

Renal: interstitial nephritis

Cardiovascular:  QTC prolongation, torsades de pointes, arrhythmias

Skin: Rash (10% of patients with rash develop severe rash which may require discontinuation of therapy)



Tablet: 320mg



Chronic bronchitis: 320mg PO q24h x 5 days

Community-acquired pneumonia: 320mg PO q24h x 7 days



Efficacy and safety not established in patients less than 18 years of age


Table 4


Disease state based dosing:

Renal failure: CrCl < 40mL/min: 160mg PO q24 hours

Hemodialysis: 160mg PO q24 hours

Peritoneal dialysis: 160mg PO q24 hours



Contraindications:  Hypersensitivity to gemifloxacin, other fluoroquinolones, or to any of its components




Drug Interactions:

Divalent cations:  aluminum, magnesium zinc, iron, calcium, antacids, sucralfate reduced bioavailability of quinolones (can cause therapeutic failure)



Category C: Risk unknown. Human studies inadequate.


Monitoring Requirements:

Therapeutic:  Culture and sensitivities, signs and symptoms of infection

Toxic:  Urinalysis, BUN, SCr, AST and ALT, Physicial examination: encephalopathic changes


Brand names/Manufacturer:  Factive/Oscient