Prolonged administration of oral phenylbutazone and firocoxib in horses has no impact on selected cytokine and growth factor concentrations in platelet-rich plasma and autologous protein solution.

This study examined the effect of long-term use of oral non-steroidal anti-inflammatory drugs (NSAIDs), phenylbutazone and firocoxib, on cytokine and growth factor levels in horse blood components, platelet-rich plasma (PRP) and autologous protein solution (APS). The research found that neither drug significantly altered the concentrations of these components, suggesting their administration prior to blood collection for PRP and APS could be safely recommended by veterinarians.

Methods

• The study involved six adult horses from the University.
• Horses were randomly given either phenylbutazone (1 gram every 12 hours) or firocoxib (57 mg every 24 hours) for a period of six days.
• Blood was drawn and processed for APS (Pro-Stride) and PRP (Restigen) before administration of the NSAIDs and seven days after (one day after stopping the NSAIDs).
• A two-week washout period ensued, in which more blood was taken at 14 and 21 days.
• The protocol was then repeated with a crossover design—where the first group administered with phenylbutazone was given firocoxib and vice versa.
• Both PRP and APS samples were examined for levels of platelets, leukocytes, cytokines (IL-1β, IL-10, IL-6, IL-8, and tumor necrosis factor-α), and growth factors (PDGF, FGF-2, and TGF-β1).
• Plasma was also tested for drug concentrations.

Results

• The results showed no significant variances in the concentrations of both growth factors and cytokines before or after prolonged NSAIDs administration.
• There were significant differences in the levels of leukocytes and platelets when comparing PRP to APS, with higher leukocyte levels at day 7 time point (T) in APS (phenylbutazone), in platelet concentrations in APS at initial time point (T0 – firocoxib), and in APS at T7 (phenylbutazone).

Conclusion

• The findings imply that these NSAIDs can be administered to horses before collecting their blood for PRP and APS processing, provided a single-day washout period is followed.