Efficacy of cyclo-oxygenase inhibition by two commercially available firocoxib products in horses.
Authors: Barton M H, Paske E, Norton N, King D, Giguère S, Budsberg S
Journal: Equine veterinary journal
Summary
# Editorial Summary: Firocoxib Formulation Efficacy in Horses Cost pressures have led many equine practitioners to administer the canine firocoxib tablet formulation off-label to horses rather than use the approved equine paste, yet the comparative efficacy of these products had not been systematically evaluated. Barton and colleagues conducted a crossover study in eight horses receiving 57 mg of either formulation daily for seven days, measuring prostaglandin E₂ (PGE₂) synthesis inhibition via ex vivo lipopolysaccharide stimulation of blood samples collected before treatment and on day 7, alongside plasma firocoxib concentrations. Both preparations produced equivalent and significant reductions in LPS-induced PGE₂ compared to untreated controls, with no statistical difference in anti-inflammatory efficacy or plasma drug concentrations between the two formulations. These findings suggest the canine chewable tablet represents a pharmacologically sound alternative where extra-label use can be legally and ethically justified, though practitioners should remain cognisant of regulatory, liability and formulation considerations when deviating from approved routes. The study importantly demonstrates that cost-driven formulary substitution does not necessarily compromise therapeutic outcomes in this instance, though such decisions warrant careful case-by-case evaluation and appropriate owner communication.
Read the full abstract on PubMed
Practical Takeaways
- •The cheaper canine chewable firocoxib product provides equivalent anti-inflammatory efficacy to the equine paste, allowing cost reduction where extra-label use is legally permissible
- •Both formulations achieve consistent PGE2 suppression by Day 7 of daily dosing, supporting their use for managing inflammation-related conditions
- •Dosing of 57 mg daily produces adequate plasma concentrations in horses regardless of formulation type
Key Findings
- •Canine chewable firocoxib formulation was as effective as equine paste formulation at reducing LPS-induced PGE2 synthesis in horses at 57 mg daily dosing
- •Both firocoxib preparations significantly decreased LPS-induced PGE2 concentrations compared to baseline by Day 7
- •No significant differences in plasma firocoxib concentrations or PGE2 reduction between canine and equine formulations
- •Control horses showed no significant change in LPS-induced PGE2 over the study period