A new study from the University of Pennsylvania’s New Bolton Center has reassuring findings regarding the impact of anti-inflammatory medications on blood-based biologic equine therapies. Researchers found that administering a dose of nonsteroidal anti-inflammatory drugs (NSAIDs) before performing platelet-rich plasma (PRP) or autologous protein solution (APS) procedures did not negatively affect some important therapeutic components.

Technically known as autologous orthobiologic therapies, PRP and APS involve concentrating growth factors and other beneficial agents from an injured horse’s own blood, and injecting the solution into the affected area to promote healing. PRP and APS are becoming increasingly popular for treating conditions such as osteoarthritis, and  tendon and ligament injuries in horses.

NSAIDs like phenylbutazone (bute) and flunixin meglumine (Banamine) not only reduce inflammation but affect other cells in the body. That’s why these medications are stopped before PRP or APS therapy begins. “Some non-steroidal anti-inflammatory drugs can affect the function of components of blood, such as platelets. There have been concerns that this may result in alterations of the important anti-inflammatory proteins released by blood components concentrated in these products,” explains Kara Brown, VMD, DACVSMR.

Pre-therapy trade-offs

Yet halting anti-inflammatory medication can increase an injured horse’s discomfort and even slow healing. Plus, Brown notes, the length of time a horse needs to go without medication before PRP or APS procedures is unclear. “There are no official guidelines for how long to remove horses from NSAIDs… prior to APS and PRP. Therefore, this differs by clinicians. However, in humans the typical recommendation is to cease administration of NSAIDs approximately three to seven days prior to obtaining blood for PRP,” she says.

The experiment

The researchers drew blood from six healthy horses and processed it for APS and PRP. Next, they gave the horses standard doses of either ketoprofen or flunixin meglumine intravenously. Then, six hours later, they drew blood and processed it for APS and PRP.

The researchers then compared the two preparations before and after administration of NSAIDs. They focused on concentrations of platelets, leukocytes, growth factors and cytokines (proteins, some of which can help control inflammation). Two weeks later, they followed the same protocols with oral phenylbutazone and firocoxib (Equioxx).

The findings

Analysis showed that there were differences in concentrations of leukocytes and platelets. But the therapeutic consequence of this finding is unclear. “There are still many questions as to whether higher or lower concentrations of leukocytes and platelets significantly affect the action of PRP and APS,” Brown notes. “Some studies suggest that higher concentrations of leukocytes could be deleterious to healing. Others seem to indicate that they are beneficial.”

Nonetheless, she says, “the good news is that the proteins (cytokines and growth factors) considered to be key in the effectiveness of these products were not significantly altered despite the admini-
stration of a single dose of these NSAIDS.”

Reference: “Single-dose nonsteroidal anti-inflammatory drugs in horses have no impact on concentrations of cytokines or growth factors in autologous protein solution and platelet-rich plasma,” American Journal of Veterinary Research, February 2024