Tranexamic acid (TXA) reduce mortality in bleeding trauma patients, with greater effect if administered early. Serum concentrations above 10 µg/mL are considered sufficient to inhibit fibrinolysis. Normally administered intravenously (i.v.), TXA can also be administered intramuscularly (i.m.). This could be advantageous in low resource and military settings, if sufficient serum concentrations can be reached in shocked patients with reduced muscular blood perfusion. Accordingly, we aimed to: (1) Determine the impact of shock on the pharmacokinetics of i.m. TXA, and (2) Compare the pharmacokinetics of i.v. versus i.m. TXA in ongoing shock. In a prospective experimental study, N = 18 Norwegian landrace pigs (40–50 kg), utilised in a surgical course in haemostatic emergency surgery, were subjected to various abdominal and thoracic trauma. After 1 h of surgery the animals were given 15 mg/kg TXA either i.v. or i.m. A control group without injury, or surgery, received intramuscular TXA. Blood samples were drawn at 0, 5, 15, 25, 35, 45, 60 and 85 min. The samples were centrifuged and analysed with liquid chromatography–tandem mass spectrometry (LC–MS/MS) for TXA serum-concentrations. In shocked pigs, i.m. administration resulted in a mean maximum serum concentration (Cmax) of 20.9 µg/mL, and i.v. administration a Cmax of 48.1 µg/mL. Cmax occurred 15 min after i.m. administration and 5 min after i.v. administration. In non-shocked swine, i.m. administration resulted in a Cmax of 36.9 µg/mL after 15 min. In all groups, mean TXA serum concentrations stayed above 10 µg/mL from administration to end of experiments. I.m. administration of TXA in shocked pigs provides serum concentrations associated with inhibition of fibrinolysis. It may be an alternative to i.v. and intraosseous administration during stabilisation and transport of trauma patients to advanced medical care.

中文翻译：

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猪模型失血性休克期间氨甲环酸的肌内摄取

氨甲环酸 (TXA) 可降低出血性创伤患者的死亡率，如果尽早给药，效果会更好。血清浓度高于 10 µg/mL 被认为足以抑制纤维蛋白溶解。通常静脉内给药 (iv)，TXA 也可以肌肉内给药 (im)。如果在肌肉血流灌注减少的休克患者中可以达到足够的血清浓度，这在资源匮乏和军事环境中可能是有利的。因此，我们旨在：(1) 确定休克对 im TXA 药代动力学的影响，以及 (2) 比较持续休克中 iv 与 im TXA 的药代动力学。在一项前瞻性实验研究中，N = 18 头挪威长白猪（40-50 公斤）在止血急诊手术的手术过程中受到各种腹部和胸部创伤。在休克猪中给予 TXA 可提供与抑制纤维蛋白溶解相关的血清浓度。在创伤患者稳定和转运到高级医疗护理期间，它可能是静脉注射和骨内给药的替代方法。