Use of in vitro assays to identify antibiotics that are cytotoxic to normal equine chondrocytes and synovial cells.
Authors: Pezzanite Lynn, Chow Lyndah, Piquini Gabriella, Griffenhagen Gregg, Ramirez Dominique, Dow Steven, Goodrich Laurie
Journal: Equine veterinary journal
Summary
# Editorial Summary Intra-articular antibiotic administration is routine in equine practice, yet the direct toxic effects of these drugs on joint tissues remain poorly characterised, and rising antimicrobial resistance demands more judicious prescribing, particularly for prophylactic use. Researchers employed in vitro assays to expose equine articular chondrocytes and synovial cells to various antibiotics at clinically relevant concentrations, measuring cell viability and inflammatory markers to identify which agents caused the most damage to normal joint tissues. Several commonly administered antibiotics demonstrated substantial cytotoxicity at standard doses—notably aminoglycosides and fluoroquinolones—whilst others proved considerably safer, with marked variation in the toxic threshold between cell types. These findings challenge current practice by suggesting that some intra-articular prophylactic protocols may be damaging healthy joint structures whilst simultaneously driving resistance, and highlight the urgent need for evidence-based dosing guidelines and reconsideration of antibiotic selection for joint use. Clinicians should consider these cytotoxicity profiles when choosing intra-articular agents, particularly in routine prophylaxis where the cost-benefit ratio of tissue damage may not justify use of the most toxic options.
Read the full abstract on PubMed
Practical Takeaways
- •Question routine prophylactic intra-articular antibiotic use in your practice, as many common choices damage healthy joint cells while potentially driving resistance
- •Work with your veterinarian to identify and use antibiotics with lower cytotoxic profiles when intra-articular injection is necessary, and ensure proper dosing protocols are established
- •Consider alternative joint health strategies and reserve intra-articular antibiotics for clear therapeutic indications rather than automatic prophylaxis
Key Findings
- •Many commonly used intra-articular antibiotics exert direct cytotoxicity to equine chondrocytes and synovial cells
- •In vitro assays can identify antibiotics with reduced cytotoxic effects on normal equine joint tissues
- •Appropriate intra-articular antibiotic doses have not been defined despite prevalent clinical usage
- •Emergence of antimicrobial resistance necessitates re-evaluation of antibiotic selection for prophylactic intra-articular use