buprenorphine and Synovitis

The objective of this study was to describe the pharmacokinetics of intra-articular (IA) administered buprenorphine in horses with lipopolysaccharide (LPS)-induced synovitis. Radiocarpal synovitis was induced in six healthy adult horses with the IA injection of LPS (0.5 ng/joint) on two occasions in a randomized cross-over design. Treatments (IA buprenorphine (IAB) at 5 μg/kg plus intravenous saline; and intravenous buprenorphine (IVB) at 5 μg/kg plus IA saline) were administered 4 h following LPS injection. Concentrations of buprenorphine were assessed in plasma and synovial fluid (SF) at 0.5, 2, 6, 12, and 24 h after administration. Pharmacokinetic parameters after IVB and IAB in plasma and synovial fluid were calculated using a nonlinear mixed effects model. IAB was detectable in SF of all horses at 24 h [median concentration of 6.2 (3.46-22.6) ng/mL]. IAB resulted in a median plasma concentration of 0.59 (0.42-1.68) ng/mL at 0.5 h and was detectable in all subjects for up to 6 h and in two horses for up to 12 h. IVB resulted in SF concentrations detected up to 6 h in all horses [median concentration of 0.12 (0.07-0.82) ng/mL]. Results suggest that IA buprenorphine remains present in the inflamed joint for at least 24 h and systemic absorption occurs.

Topics: Animals; Buprenorphine; Horse Diseases; Horses; Injections, Intra-Articular; Lipopolysaccharides; Synovial Fluid; Synovitis

This study evaluated the analgesia effects of the epidural administration of 0.1 mg/kg bodyweight (BW) of morphine or 5 μg/kg BW of buprenorphine in ponies with radiocarpal joint synovitis. Six ponies were submitted to 3 epidural treatments: the control group (C) received 0.15 mL/kg BW of a 0.9% sodium chloride (NaCl) solution; group M was administered 0.1 mg/kg BW of morphine; and group B was administered 5 μg/kg BW of buprenorphine, both diluted in 0.9% NaCl to a total volume of 0.15 mL/kg BW administered epidurally at 10 s/mL. The synovitis model was induced by injecting 0.5 ng of lipopolysaccharide (LPS) in the left or right radiocarpal joint. An epidural catheter was later introduced in the lumbosacral space and advanced up to the thoracolumbar level. The treatment started 6 h after synovitis induction. Lameness, maximum angle of carpal flexion, heart rate, systolic arterial pressure, respiratory rate, temperature, and intestinal motility were evaluated before LPS injection (baseline), 6 h after LPS injection (time 0), and 0.5, 1, 2, 4, 6, 8, 10, 12, 16, 20, and 24 h after treatments. Although the model of synovitis produced clear clinical signs of inflammation, the lameness scores in group C were different from the baseline for only up to 12 h. Both morphine and buprenorphine showed a reduction in the degree of lameness starting at 0.5 and 6 h, respectively. Reduced intestinal motility was observed at 0.5 h in group M and at 0.5 to 1 h in group B. Epidural morphine was a more effective analgesic that lasted for more than 12 h and without side effects. It was concluded that morphine would be a valuable analgesic option to alleviate joint pain in the thoracic limbs in ponies.

Topics: Analgesia, Epidural; Analgesics, Opioid; Animals; Buprenorphine; Carpal Joints; Female; Horse Diseases; Horses; Lameness, Animal; Lipopolysaccharides; Male; Morphine; Pain; Pain Measurement; Synovitis