A Review of Fluoroquinolones with a Focus on Veterinary-Approved Agents

Fluoroquinolones are broad-spectrum, bactericidal antibacterial agents used in both human and veterinary medicine. Some human-approved drugs are used off label in veterinary medicine while veterinary-approved drugs are not used in humans. Veterinary-approved fluoroquinolones are used on both food and companion animals and against a wide range of clinical indications including infections of the urinary tract, respiratory tract, skin and skin structure, mammary gland and others. Not all veterinary-approved fluoroquinolones have the same clinical indication and it is important to understand these important differences. A recently approved for food animals agent called pradofloxacin is characterized as being dual targeting in that it simultaneously inhibits DNA gyrase (topoisomerase II) and Topoisomerase IV-two enzymes critical for DNA replication. Simultaneous targeting of two enzymes is argued to reduce the likelihood for resistance selection. This article reviews veterinary-approved fluoroquinolones including an overview of the drugs, in vitro activity including bactericidal properties, pharmacokinetic/pharmacodynamics, antimicrobial resistance, anti-inflammatory properties and clinical trial results. Appropriate use of this important class of antimicrobial agents is essential for clinical success and long-term viability of these compounds.