Molecule

Drug Groups

approved; investigational

Description

Gemifloxacin is an oral broad-spectrum quinolone antibacterial agent used in the treatment of acute bacterial exacerbation of chronic bronchitis and mild-to-moderate pneumonia. Gemifloxacin acts by inhibiting DNA synthesis through the inhibition of both DNA gyrase and topoisomerase IV, which are essential for bacterial growth.

Indication

For the treatment of bacterial infection caused by susceptible strains such as S. pneumoniae, H. influenzae, H. parainfluenzae, or M. catarrhalis, S. pneumoniae (including multi-drug resistant strains [MDRSP]), M. pneumoniae, C. pneumoniae, or K. pneumoniae.

Pharmacology

Gemifloxacin is a quinolone/fluoroquinolone antibiotic. Gemifloxacin is bactericidal and its mode of action depends on blocking of bacterial DNA replication by binding itself to an enzyme called DNA gyrase, which allows the untwisting required to replicate one DNA double helix into two. Notably the drug has 100 times higher affinity for bacterial DNA gyrase than for mammalian. Gemifloxacin is a broad-spectrum antibiotic that is active against both Gram-positive and Gram-negative bacteria.

Affected Organisms

Biotransformation

Gemifloxacin is metabolized to a limited extent by the liver. All metabolites formed are minor (<10% of the administered oral dose); the principal ones are N-acetyl gemifloxacin, the E-isomer of gemifloxacin and the carbamyl glucuronide of gemifloxacin.

Absorption

Rapidly absorbed from the gastrointestinal tract. The absolute bioavailability averages approximately 71%.

Half Life

7 (± 2) hours

Protein Binding

60-70%

Elimination

Gemifloxacin and its metabolites are excreted via dual routes of excretion.Following oral administration of gemifloxacin to healthy subjects, a mean (± SD) of 61 ± 9.5% of the dose was excreted in the feces and 36 ± 9.3% in the urine as unchanged drug and metabolites. The mean (± SD) renal clearance following repeat doses of 320 mg was approximately 11.6 ± 3.9 L/hr (range 4.6-6 L/hr), which indicates active secretion is involved in the renal excretion of gemifloxacin.

Distribution

* 1.66 to 12.12 L/kg

Clearance

* renal cl=11.6+/- 3.9 L/hr [Healthy subjects receiving repeat doses of 320 mg orally]

External Links