Tramadol Steady-State Pharmacokinetics of Immediate-Release Capsules and Sustained-Release Tablets in Dogs

Tramadol is a veterinary analgesic for dogs. In this study, the steady-state pharmacokinetics of sustained-release (SR) tablet (Tramagetic OD®) and immediate-release capsules (IR) were compared. crossover design, six dogs received five doses IR 50 mg four times day (qid), or two SR 200 once (sid). Eight blood samples collected per dog, formulation, up to 6 24 h after last dose, respectively. Serum concentrations tramadol its metabolites measured with LC-MS/MS. Metabolite M1 levels below lower limit quantification (LLOQ) in all samples. The non-compartmental analysis time–concentration data showed later Tmax formulation (median 6.00 (3.00–9.00)) Cmax/D 7.74 µg/L/mg/kg (0.09–25.3)) compared 1.75 (0.75–2.00) median 11.1 (4.8–70.4)). AUCtau/D administration was 55.5 × kg µg/L/mg (0–174.1) 29.8 (12.2–140.8) administration. terminal elimination half-lives 2.38 (1.77–6.22) 1.70 (0.95–2.11) formulations, Strong conclusions cannot be drawn from study because high percentage that LLOQ great interindividual variability, but these results suggest Tramagetic OD can administered less frequently