Pharmacokinetics, pharmacodynamics and local tolerance at injection site of marbofloxacin administered by regional intravenous limb perfusion in standing horses.

The research investigates the effectiveness and safety of using marbofloxacin, a type of antibiotic, administered to horses through a technique called regional intravenous limb perfusion. The study found that this method can produce high concentrations of the antibiotic in the synovial fluid, which is around the horse’s joint, without any observed negative effects.

Methodology

• The research used six adult horses. The regional intravenous limb perfusion technique was conducted on the forelimbs of the sedated horses, with marbofloxacin injected randomly into one forelimb.
• The other limb served as a control, receiving a saline solution instead.
• The researchers collected blood samples and synovial fluid from the joint of the limb that received the marbofloxacin injection both before and at intervals after the procedure which enabled them to determine the drug concentrations in these areas.
• All injection sites were assessed before, as well as 24 and 48 hours after the procedure using ultrasonography, measurements of the circumference of the limb, and a visual inflammation score determined by blinded veterinarians.

Findings

• The researchers did not observe any negative effects related to the procedure or the antibiotic. The study found high concentrations of marbofloxacin in the synovial fluid.
• Measurements of the effect of the drug over time (Area Under the Curve from zero to infinity or AUCINF) were found to be substantially higher in the synovial fluid compared to the plasma.
• Efficacy indices, which predict the success of the treatment against certain infections, suggested a favourable outcome in treating synovial fluid infections instigated by specific bacteria, including Enterobacteria and Staphylococcus Aureus.
• Comparisons between the limbs that received marbofloxacin and the control limbs showed no significant differences in lameness, visible inflammation scores, limb circumference, and the ultrasonographic appearance of the veins.
• However, the limbs where marbofloxacin was injected showed a greater thickness in the subcutaneous layer compared to the control limbs.

Conclusions

• The study concluded that administering marbofloxacin via regional intravenous limb perfusion could provide a safe and effective treatment for infections of the lower limb caused by susceptible organisms.