Carbon hemoperfusion markedly reduces serum meloxicam concentrations in dogs with meloxicam toxicosis

Objective: To investigate the efficacy of synthetically derived activated carbon hemoperfusion (cHP) by measuring serum meloxicam concentration in dogs with meloxicam toxicosis. Methods: 5 dogs with meloxicam overdose that underwent cHP at 3 teaching hospitals between January 2023 and March 2026 were identified. Dogs that had serum meloxicam concentrations measured were included. For case 1, in-series cHP and hemodialysis were performed. Based on case 1 data, standalone cHP was used for cases 2 to 5. Serum meloxicam concentration was measured via ultra-performance liquid chromatography-tandem mass spectrometry. Results: Median ingested meloxicam dose was 16.7 mg/kg (range, 1.4 to 168.8). Median blood volumes processed were 2 L/kg (range, 1.36 to 2.56) over 2.2 hours (range, 1.5 to 2.6). During cHP, meloxicam half-life was 0.4 to 1 hour versus 5.1 to 16.6 hours post-cHP, and median clearance was 6.52 mL/kg/min (range, 3.81 to 10.42) versus 0.49 mL/kg/min post-cHP (range, 0.22 to 0.72). Median extracorporeal elimination constant from 5 dogs was 1.24 (range, 0.68 to 1.95), 13.8 times faster than the intrinsic elimination constant of 0.09 from 3 dogs (range, 0.04 to 0.14). After cHP, a rebound phenomenon (47.2% increase, approximately 5 hours later) was noted in 3 dogs. All dogs were discharged in 72 hours, with 1 dog developing International Renal Interest Society Grade II acute kidney injury during hospitalization that recovered with supportive care. Conclusions: Carbon hemoperfusion markedly reduced serum meloxicam concentrations in dogs with meloxicam toxicosis and substantially shortened meloxicam half-life. Clinical Relevance: Dogs that underwent timely cHP had excellent short-term outcomes, and cHP should be considered in dogs with high-dose meloxicam ingestion.