Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA.
Equine Vet J. 2012 Jul;44(4):453-8. doi: 10.1111/j.2042-3306.2011.00459.x. Epub 2011 Sep 25.
Minocycline holds great potential for use in horses not only for its antimicrobial effects but also for its anti-inflammatory and neuroprotective properties. However, there are no pharmacokinetic or safety data available regarding the use of oral minocycline in horses.
To determine pharmacokinetics, safety and penetration into plasma, synovial fluid, aqueous humour (AH) and cerebral spinal fluid (CSF) of minocycline after oral administration of multiple doses in horses and to determine the minimum inhibitory concentrations (MIC) of minocycline for equine pathogenic bacteria.
Six horses received minocycline (4 mg/kg bwt q. 12 h for 5 doses). Thirty-three blood and 9 synovial fluid samples were collected over 96 h. Aqueous humour and CSF samples were collected 1 h after the final dose. Minocycline concentrations were measured using high pressure liquid chromatography. The MIC values of minocycline for equine bacterial isolates were determined.
At steady state, the mean ± s.d. peak concentration of minocycline in the plasma was 0.67 ± 0.26 µg/ml and the mean half-life was 11.48 ± 3.23 h. The highest trough synovial fluid minocycline concentration was 0.33 ± 0.12 µg/ml. The AH concentration of minocycline was 0.09 ± 0.03 µg/ml in normal eyes and 0.11 ± 0.04 µg/ml in blood aqueous barrier-disrupted eyes. The mean CSF concentration of minocycline was 0.38 ± 0.09 µg/ml. The MIC values were determined for 301 isolates. Minocycline concentrations were above the MIC(50) and MIC(90) for many gram-positive equine pathogens.
This study supports the use of orally administered minocycline at a dose of 4 mg/kg bwt every 12 h for the treatment of nonocular infections caused by susceptible (MIC ≤ 0.25 µg/ml) organisms in horses. Further studies are required to determine the dose that would be effective for the treatment of ocular infections.
米诺环素不仅具有抗菌作用，而且具有抗炎和神经保护作用，因此在马中具有很大的应用潜力。然而，目前尚无关于马口服米诺环素的药代动力学或安全性数据。
确定马多次口服米诺环素后的药代动力学、安全性和向血浆、滑液、房水（AH）和脑脊液（CSF）的渗透情况，并确定米诺环素对马致病性细菌的最低抑菌浓度（MIC）。
六匹马接受米诺环素（4 mg/kg bwt q. 12 h 共 5 剂）。在 96 小时内采集 33 份血液和 9 份滑液样本。在最后一次给药后 1 小时采集房水和 CSF 样本。使用高压液相色谱法测量米诺环素浓度。确定米诺环素对马分离细菌的 MIC 值。
在稳态时，米诺环素在血浆中的平均峰浓度±标准差为 0.67±0.26 µg/ml，平均半衰期为 11.48±3.23 h。滑液中米诺环素的最高谷浓度为 0.33±0.12 µg/ml。正常眼房水中米诺环素浓度为 0.09±0.03 µg/ml，血房水屏障破坏眼房水中米诺环素浓度为 0.11±0.04 µg/ml。米诺环素的平均 CSF 浓度为 0.38±0.09 µg/ml。测定了 301 株分离物的 MIC 值。米诺环素浓度高于许多革兰氏阳性马病原体的 MIC(50)和 MIC(90)。
本研究支持使用口服米诺环素，剂量为 4 mg/kg bwt，每 12 小时一次，治疗敏感（MIC≤0.25 µg/ml）的微生物引起的非眼部感染。需要进一步研究确定治疗眼部感染的有效剂量。
