Modis Competence Center, Modis Life Sciences Belgium, Mureșului 9, 400000, Cluj-Napoca, Romania.
Department of Biochemistry, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine, Calea Mănăştur 3-5, 400372, Cluj-Napoca, Romania.
Int Ophthalmol. 2021 Feb;41(2):465-473. doi: 10.1007/s10792-020-01596-x. Epub 2020 Oct 23.
To evaluate the corneal anesthetic effect following topical application of tramadol alone and in combination with dexmedetomidine, and compare it to proparacaine, in clinically healthy rats.
A randomized, crossover study was performed. Twenty Wistar albino rats (n = 40 eyes) were used. Corneal touch threshold (CTT) measurements (in mm) were obtained using a Cochet-Bonnet aesthesiometer. CTT measurements were obtained at baseline, 1-min following application of the topical anesthetic agent, and repeated at 5-min intervals up to 75 min. The topical protocol involved 3 treatment conditions, separated by a 2-week washout period: proparacaine, tramadol alone, and tramadol in combination with dexmedetomidine.
CTT values were significantly decreased compared to baseline at each timepoint until completion of the 75-min evaluation in all treated eyes, regardless of the assigned treatment (p < 0.0083). With tramadol, complete corneal anesthesia (CTT = 0) was achieved within 1-5 min in 18 eyes and ranged from 5 to 25 min. Co-administration of dexmedetomidine to tramadol resulted in significantly increased CTT values from 5 to 20 min following topical application, compared to tramadol alone (p < 0.0083), and complete corneal anesthesia was achieved in only 14 out of 20 treated eyes.
Tramadol might be a useful alternative to topical anesthetic agents, providing a dose-related corneal anesthetic effect. Co-administration of dexmedetomidine does not potentiate its anesthetic effect. The underlying mechanism(s) of drug antagonism between tramadol and dexmedetomidine remains to be determined.
评估曲马多单独和联合右美托咪定局部应用后的角膜麻醉效果，并与丙美卡因进行比较，以评估其在临床健康大鼠中的效果。
这是一项随机交叉研究。使用 20 只 Wistar 白化大鼠（n=40 只眼）。使用 Cochet-Bonnet 触觉计测量角膜触觉阈值（CTT）（以毫米为单位）。在基线时、局部麻醉剂应用后 1 分钟以及直至 75 分钟的 5 分钟间隔时间内进行 CTT 测量。局部用药方案包括 3 种治疗条件，每种治疗条件之间间隔 2 周洗脱期：丙美卡因、曲马多单独使用和曲马多联合右美托咪定。
与基线相比，所有治疗眼在每个时间点的 CTT 值均显著降低，直至 75 分钟评估结束（p<0.0083）。使用曲马多，18 只眼在 1-5 分钟内即可实现完全角膜麻醉（CTT=0），范围在 5 至 25 分钟之间。与曲马多单独使用相比，右美托咪定与曲马多联合使用可使角膜触觉计值在 5 至 20 分钟内显著升高（p<0.0083），且仅 20 只治疗眼中的 14 只眼实现了完全角膜麻醉。
曲马多可能是局部麻醉剂的一种有用替代品，可产生剂量相关的角膜麻醉效果。右美托咪定的联合应用不会增强其麻醉效果。曲马多和右美托咪定之间药物拮抗的潜在机制仍有待确定。
