Department of Production Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland.
Research Centre for Animal Welfare, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland.
J Vet Pharmacol Ther. 2024 Mar;47(2):143-149. doi: 10.1111/jvp.13412. Epub 2023 Oct 28.
Meloxicam is routinely used for pain alleviation in pre-ruminant calves during husbandry procedures. The pharmacokinetics of a single dose (0.5 mg/kg) of meloxicam was investigated after intravenous (IV), subcutaneous (SC), and oral (PO) administration in 30 pre-ruminant calves. Each group included 10 calves. Oral meloxicam was administered at least 1 h after feeding. Plasma samples were collected for up to 168 h, and the meloxicam concentration was analysed with liquid chromatography and mass spectrometry, followed by a noncompartmental pharmacokinetic analysis. The maximum meloxicam concentrations in plasma were 1.91 ± 0.27 μg/mL and 1.77 ± 0.16 μg/mL after SC and PO routes, respectively. The time of maximum concentration was 7.6 ± 2.8 h after SC and 10.0 ± 5.7 h after PO administration. The approximate bioavailability of meloxicam was 97% for SC and PO routes. The elimination half-lives were 79.2 ± 12.4, 84.6 ± 24.8, and 84.8 ± 22.3 h after IV, SC, and PO routes, respectively. The results suggest that the therapeutic meloxicam concentrations in plasma that are required for pain relief in other species, such as horses, may be maintained for several days following a single dose (0.5 mg/kg) administered IV, SC, or PO in calves.
在饲养过程中，美洛昔康通常被用于缓解反刍前小牛的疼痛。本研究在 30 头反刍前小牛中分别进行了静脉（IV）、皮下（SC）和口服（PO）给予 0.5mg/kg 美洛昔康单剂量后的药代动力学研究。每组包括 10 头小牛。PO 给予美洛昔康至少在进食后 1 小时。采集了长达 168 小时的血浆样本，并使用液相色谱-质谱法分析了美洛昔康的浓度，随后进行了非房室药代动力学分析。SC 和 PO 途径的最大血浆美洛昔康浓度分别为 1.91±0.27μg/mL 和 1.77±0.16μg/mL。最大浓度时间分别为 SC 后 7.6±2.8 小时和 PO 后 10.0±5.7 小时。SC 和 PO 途径的美洛昔康近似生物利用度分别为 97%。IV、SC 和 PO 途径的消除半衰期分别为 79.2±12.4、84.6±24.8 和 84.8±22.3 小时。结果表明，对于其他物种（如马）而言，缓解疼痛所需的治疗性美洛昔康血浆浓度可能在静脉、皮下或口服给予 0.5mg/kg 单剂量后持续数天。
