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.