Time required to achieve maximum amikacin concentration in the synovial fluid of the tarsocrural joint following administration of the drug by intravenous regional limb perfusion in horses.

The research paper examines the amount of time required for the drug amikacin to reach maximum concentration in the synovial fluid of the tarsocrural joint in horses after administering the drug intravenously. The findings suggest that, in healthy horses, maintaining a tourniquet for 20 minutes after this procedure is enough to achieve therapeutic amikacin concentrations.

Research Methods and Findings

• The study involved seven healthy adult horses. They were sedated and restrained in a standing position while a tourniquet was applied to a randomly chosen hind limb.
• Amikacin sulfate was diluted in a saline solution and administered to the saphenous vein using a peristaltic pump.
• Samples of tarsocrural synovial fluid were collected at intervals of 5-minute starting from 5 up to 30 minutes after completing the infusion.
• The sampled fluids were inspected to quantify the concentration of amikacin using a method called fluorescence polarization immunoassay.
• The results revealed that the median maximum synovial fluid amikacin concentration was 450.5 μg/mL, ranging from 304.7 to 930.7 μg/mL. The median time to reach this maximum concentration was 25 minutes, with a range of 20 to 30 minutes.
• The researchers noted that therapeutic concentrations were achieved at 20 minutes after the process in all horses.

Conclusion

• The results suggest that in healthy horses, practitioners should maintain a tourniquet for 20 minutes after intravenous regional limb perfusion of amikacin in a saphenous vein, to reach therapeutic concentrations of the drug in the tarsocrural joint.

Limitations

• One horse was excluded from the data analysis because the volume of synovial fluid obtained for evaluation during multiple points in the study was not sufficient.