Drug Groups

approved; investigational

Description

Moxifloxacin is a synthetic fluoroquinolone antibiotic agent. Bayer AG developed the drug (initially called BAY 12-8039) and it is marketed worldwide (as the hydrochloride) under the brand name Avelox (in some countries also Avalox) for oral treatment.

Indication

For the treatment of sinus and lung infections such as sinusitis, pneumonia, and secondary infections in chronic bronchitis. Also for the treatment of bacterial conjunctivitis (pinkeye).

Pharmacology

Moxifloxacin is a quinolone/fluoroquinolone antibiotic. Moxifloxacin can be used to treat infections caused by the following bacteria: Aerobic Gram-positive microorganisms: Corynebacterium species, Micrococcus luteus, Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus haemolyticus, Staphylococcus hominis, Staphylococcus warneri, Streptococcus pneumoniae, and Streptococcus viridans group. Aerobic Gram-negative microorganisms: Acinetobacter lwoffii, Haemophilus influenzae, and Haemophilus parainfluenzae. Other microorganisms: Chlamydia trachomatis.
Moxifloxacin 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. Moxifloxacin is a broad-spectrum antibiotic that is active against both Gram-positive and Gram-negative bacteria.

Toxicity

Symptoms of overdose include CNS and gastrointestinal effects such as decreased activity, somnolence, tremor, convulsions, vomiting, and diarrhea. The minimal lethal intravenous dose in mice and rats is 100 mg/kg.

Affected Organisms

Biotransformation

Approximately 52% or oral or intravenous dose is metabolized via glucuronide and sulphate conjugation. The cytochrome P450 system is not involved in metabolism. The sulphate conjugate accounts for 38% of the dose, and the glucuronide conjugate accounts for 14% of the dose.

Absorption

Well absorbed from the gastrointestinal tract. Absolute oral bioavailability is approximately 90%. Food has little effect on absorption.

Half Life

11.5-15.6 hours (single dose, oral)

Protein Binding

50% bound to serum proteins, independent of drug concentration.

Elimination

Approximately 45% of an oral or intravenous dose of moxifloxacin is excreted as unchanged drug (~20% in urine and ~25% in feces).

Distribution

* 1.7 to 2.7 L/kg

Clearance

* 12 +/- 2 L/hr

References

External Links