Mechanism of Action

The bactericidal action of moxifloxacin results from inhibition of the topoisomerase II (DNA gyrase) and topoisomerase IV required for bacterial DNA replication, transcription, repair, and recombination.


The mechanism of action for fluoroquinolones, including moxifloxacin, is different from that of macrolides, beta-lactams, aminoglycosides, or tetracyclines; therefore, microorganisms resistant to these classes of drugs may be susceptible to moxifloxacin. Resistance to fluoroquinolones occurs primarily by a mutation in topoisomerase II (DNA gyrase) or topoisomerase IV genes, decreased outer membrane permeability or drug efflux. In vitro resistance to moxifloxacin develops slowly via multiple-step mutations. Resistance to moxifloxacin occurs in vitro at a general frequency of between 1.8 x 10–9 to < 1 x 10–11 for Gram-positive bacteria.

Cross Resistance

Cross-resistance has been observed between moxifloxacin and other fluoroquinolones against Gram-negative bacteria. Gram-positive bacteria resistant to other fluoroquinolones may, however, still be susceptible to moxifloxacin. There is no known cross-resistance between moxifloxacin and other classes of antimicrobials.

Antimicrobial Activity

Moxifloxacin has been shown to be active against most isolates of the following bacteria, both in vitro and in clinical infections [see Indications and Usage (1)].

Gram-positive bacteria

Enterococcus faecalis

Staphylococcus aureus

Streptococcus anginosus

Streptococcus constellatus

Streptococcus pneumoniae (including multi-drug resistant isolates [MDRSP] **)

Streptococcus pyogenes

**MDRSP, Multi-drug resistant Streptococcus pneumoniae includes isolates previously known as PRSP (Penicillin-resistant S. pneumoniae), and are isolates resistant to two or more of the following antibiotics: penicillin (MIC) ≥2 mcg/mL), 2nd generation cephalosporins (for example, cefuroxime), macrolides, tetracyclines, and trimethoprim/sulfamethoxazole.

Gram-negative bacteria

Enterobacter cloacae

Escherichia coli

Haemophilus influenzae

Haemophilus parainfluenzae

Klebsiella pneumoniae

Moraxella catarrhalis

Proteus mirabilis

Yersinia pestis

Anaerobic bacteria

Bacteroides fragilis

Bacteroides thetaiotaomicron

Clostridium perfringens

Peptostreptococcus species

Other microorganisms

Chlamydophila pneumoniae

Mycoplasma pneumoniae

The following in vitro data are available, but their clinical significance is unknown. At least 90 percent of the following bacteria exhibit an in vitro minimum inhibitory concentration (MIC) less than or equal to the susceptible breakpoint for moxifloxacin against isolates of similar genus or organism group. However, the efficacy of AVELOX in treating clinical infections due to these bacteria has not been established in adequate and well controlled clinical trials.

Gram-positive bacteria

Staphylococcus epidermidis

Streptococcus agalactiae

Streptococcus viridans group

Gram-negative bacteria

Citrobacter freundii

Klebsiella oxytoca

Legionella pneumophila

Anaerobic bacteria

Fusobacterium species

Prevotella species

Drug Label Information | Brands:

Avelon, Bayer Pharma AG
Avelox, Bayer Pharma AG
Floxsafe, MSN Laboratories Private Limited.
M-Flox , Hetero Labs Limited
Mahaflox , Mankind Pharma Ltd
Maxim , Jamjoom Pharmaceuticals Company Limited
Micromox, Micro Labs Limited India
Milflox, Sun Pharmaceutical Industries Limited
Molox , CCL Pharma (pvt) Ltd
Moxaf , Guilin Pharmaceutical (Shanghai) Co. Ltd.
Moxi-Bio , Sava Healthcare Ltd
Moxidoc, Medisel Kenya Ltd.
Moxiget, Getz Pharma (Pvt) Limited
Moxima , Stallion Laboratories Pvt Ltd
Moximac, Macleods Pharmaceuticals Limited
Moxicip, Cipla
Moxeque , Questa Care Inc
Plenmoxi , Unosource Pharma Ltd
Zeebact , Zest Pharma

Moxifloxacin is a fluoroquinolone antibacterial drug indicated for treating infections in adults ≥ 18 years of age caused by designated, susceptible bacteria.

  • Community Acquired Pneumonia
  • Skin and Skin Structure Infections: Uncomplicated and Complicated
  • Complicated Intra-Abdominal Infections
  • Acute Bacterial Sinusitis
  • Acute Bacterial Exacerbation of Chronic Bronchitis


Known hypersensitivity to moxifloxacin or other quinolones.


Most common reactions (≥ 3%) were nausea, diarrhea, headache, and dizziness.


Anticoagulant effect of warfarin may be enhanced. Monitor prothrombin time/INR, watch for bleeding.

Class IA and Class III antiarrhythmics:
Proarrhythmic effect may be enhanced. Avoid concomitant use.

Prescription Category:
DDA Schedule:
Dosage Forms:
Routes of Administration:
Protein Binding:
Elimination Half life:
Drug Indentifiers:

References/ Citation:

Prescription Category:
DDA Schedule:
Dosage Forms:
Routes of Administration:
Protein Binding:
Elimination Half life:
Drug Indentifiers:

References/ Citation: