Departments of Obstetrics and Gynaecology, Biochemistry, and Pharmacology, University of Jaffna, and the Department of Anesthesiology, Teaching Hospital-Jaffna, Jaffna, Sri Lanka; and the Molecular and Clinical Sciences Research Institute, St George's, University of London, London, United Kingdom.
Obstet Gynecol. 2020 Apr;135(4):945-948. doi: 10.1097/AOG.0000000000003750.
To evaluate the pharmacokinetics of tranexamic acid after oral administration to postpartum women.
We conducted a single-center pharmacokinetic study at Teaching Hospital-Jaffna, Sri Lanka, on 12 healthy postpartum women who delivered vaginally. After oral administration of 2 g of immediate-release tranexamic acid 1 hour after delivery, pharmacokinetic parameters were measured on plasma samples at 0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, 6, 8, 10, and 12 hours. Plasma tranexamic acid concentrations were determined by high-performance liquid chromatography. The outcome measures were maximum observed plasma concentration, time to maximum plasma concentration, time to reach effective plasma concentration, time period effective serum concentration lasted, area under the curve for drug concentration, and half-life of tranexamic acid.
The mean maximum observed plasma concentration was 10.06 micrograms/mL (range 8.56-12.22 micrograms/mL). The mean time to maximum plasma concentration was 2.92 hours (range 2.5-3.5 hours). Mean time taken to reach the effective plasma concentration of 5 micrograms/mL and the mean time this concentration lasted were 0.87 hours and 6.73 hours, respectively. Duration for which plasma tranexamic acid concentration remained greater than 5 micrograms/mL was 5.86 hours. Half-life was 1.65 hours. Area under the curve for drug concentration was 49.16 micrograms.h/mL (range 43.75-52.69 micrograms.h/mL).
Clinically effective plasma concentrations of tranexamic acid in postpartum women may be achieved within 1 hour of oral administration. Given the promising pharmacokinetic properties, we recommend additional studies with larger sample sizes to investigate the potential of oral tranexamic acid for the treatment or prophylaxis of postpartum hemorrhage.
评估产后妇女口服氨甲环酸的药代动力学。
我们在斯里兰卡贾夫纳教学医院进行了一项单中心药代动力学研究，共纳入 12 名阴道分娩的健康产后妇女。产后 1 小时，口服 2 g 速释氨甲环酸，在 0、0.5、1、1.5、2、2.5、3、3.5、4、5、6、8、10 和 12 小时采集血浆样本，测定药代动力学参数。采用高效液相色谱法测定血浆氨甲环酸浓度。主要结局指标为最大血药浓度、达峰时间、达有效血药浓度时间、有效血药浓度持续时间、药物浓度曲线下面积和氨甲环酸半衰期。
平均最大血药浓度为 10.06 微克/毫升（范围 8.56-12.22 微克/毫升）。平均达峰时间为 2.92 小时（范围 2.5-3.5 小时）。达到 5 微克/毫升有效血药浓度的平均时间和该浓度持续的平均时间分别为 0.87 小时和 6.73 小时。氨甲环酸浓度大于 5 微克/毫升的持续时间为 5.86 小时。半衰期为 1.65 小时。药物浓度曲线下面积为 49.16 微克·小时/毫升（范围 43.75-52.69 微克·小时/毫升）。
产后妇女口服氨甲环酸 1 小时内可达到有临床意义的血药浓度。鉴于其有良好的药代动力学特性，我们建议开展更大样本量的研究，以探讨口服氨甲环酸治疗或预防产后出血的潜力。
