Effects of Routine Antithrombotic-Adjusted Dose of Rivaroxaban and Nadroparin Calcium on Tendon Healing of Rats: An Experimental Study

Introduction Achilles tendon injury necessitates thromboembolism prophylaxis after repair. This study aimed to investigate the effects of antithrombotic-adjusted prophylactic doses of nadroparin calcium and rivaroxaban on Achilles tendon healing. Materials and Methods Twenty-four young adult male Wistar Albino type rats were randomly divided into three groups. All rats underwent a full-thickness surgical incision of the Achilles tendon, followed by primary repair. After the procedure, group 1 was determined as the control group and received no medication. Group 2 received 2.03 mg/kg rivaroxaban daily via gastric lavage once daily, and group 3 was given subcutaneous 114 IU AXa nadroparin calcium once daily for 28 days. After euthanization, the degrees of inflammation, neovascularization, fibroblastic activity, and collagen fiber sequencing were examined and scored for histopathological evaluation. The Statistical Package for Social Science (SPSS) version 21.0 for Windows software (SPSS, Inc., Chicago, Illinois, United States) was used for all statistical analyses. The number of inflammatory cells, capillary vessels, and fibroblasts, which met the parametric tests’ assumptions, were compared between three independent groups by one-way analysis of variance. The significance level was set at p-value < 0.05. Results Histological examination of the group 1 sample showed the presence of inflammatory cells, an increase in the number of fibroblasts, and sequencing of collagen fibers scattered. The presence of inflammatory cells, remarkable increases in the number of fibroblasts, the presence of mature collagen fibers, and regular sequencing of collagen fibers regular were shown in groups 2 and 3. There were statistically significant differences between the groups regarding the number of inflammatory cells and fibroblasts. In group 2, the number of inflammatory cells was lower than in groups 1 and 3. Elsewhere, the number of fibroblasts was higher in group 1 compared than in groups 2 and 3. Conclusion Both rivaroxaban and nadroparin calcium in their daily dosage have a beneficial effect on Achilles tendon healing.

Pharmacokinetics of low molecular weight heparins in thrombosis, complicate the treatment of children with cancer

Objective: to evaluate the pharmacokinetics of nadroparin and dalteparin in thrombosis complicating the treatment of children with malignant neoplasms.Materials and methods. The results of 52 pharmacokinetic studies performed in 34 patients with malignant neoplasms, whose treatment was complicated by venous thrombosis, were analyzed. The age of the patients is from 7 to 18 years, he median is 14.5 years. Depending on the value of daily dose and type of heparin administered, the results of pharmacokinetic studies were divided into 6 groups. Dalteparin sodium: during period of chemotherapy induced thrombocytopenia, subcutaneous injection at a dose of 51.0 (40.0-72.0) anti Xa IU/kg every 12 hours - 6 studies; subcutaneous injection every 12 hours at a dose of 100.5 (91.0-141.0) anti Xa IU/kg - 18 observations; long-term continuous administration at a constant rate at a daily dose of 201.0 (180.0-265.0) anti Xa IU/kg - 6 pharmacokinetic observations. Nadroparin calcium: 62.0 (53.0-71.0) anti Xa IU/kg every 12 hours - 6 studies; 93.5 (80.0-117.0) anti Xa IU/kg every 12 hours - 10 observations; subcutaneous injection at a dose of 203.0 (170.0-236.0) anti Xa IU/kg once a day - 6 pharmacokinetic observations.Results. At steady-state, the area under the pharmacokinetic curve (AUC) of dalteparin and nadroparin, regardless of the mode of administration, depended on the maximum specific activity and half-life. No relationship was found for dalteparin between AUC and endogenous creatinine clearance. In contrast to dalteparin, the AUC after administration of na-droparin was closely related to endogenous creatinine clearance. The increase in chronometric indices indirectly reflected the presence of an anticoagulant in the blood, but did not allow an objective assessment of therapeutic effect achievement, recorded by the degree of thrombin generation inhibition.Conclusion. There were no significant advantages of nadroparin compared with dalteparin when using in comparable doses in the case of venous thrombosis, complicated the treatment of children with malignant neoplasms. Subcutaneous administration of 50 % nadroparin calcium daily dose with 12 hours interval is preferred over a single administration of 100 % daily dose every 24 hours. It is mandatory to monitor the administration of low molecular weight heparins in children with oncological diseases in order to make a decision on the adequacy of anticoagulant dose to the therapeutic range.