The study's objective is to evaluate the effectiveness and safety of tranexamic acid for adult patients with moderate to severe TBI.With the research question as "Does TXA reduce the incidence of progressive intracranial haemorrhage by 50% compared to placebo in moderate to severe adult TBI patients at Khon Kaen Hospital?"

Traumatic brain injury (TBI) is a major public health problem with poor outcome especially with progressive intracranial haemorrhage (PIH) in severe patients. There are links between coagulopathic change after brain injury and delayed traumatic haemorrhage revealed by CT brain. Antifibrinolytic treatment can reduce blood loss after surgery and perhaps in moderate to severe TBI by similar haemostatic responses. It is justified to determine benefit for reversing hyperfibrinolysis after TBI. Tranexamic acid (TXA) has been shown to have significant clinical benefit in effectively reducing surgical bleeding in systematic reviews. It has been shown to have no effect on coagulation parameters and no demonstrated harmful effect in systematic reviews. This study is designed to determine the effectiveness of TXA in preventing PIH in patients with moderate to severe TBI. The treatment regimen if effective can be applied in general trauma practice worldwide.

Inclusion Criteria:

• moderate to severe injuries(post-resuscitation scores GCS 4-12)
• age >= 16 year
• non-penetrating TBI in 8 hours onset
• first CT brain in 8 hours onset
• non neurosurgical OR in 8 hours onset

Exclusion Criteria:

• patients with coagulopathy
• serum creatinine over than 2 mg%
• with associated major organ injury requiring surgery within 8 hours of injury
• pregnancy
• receiving any medication which affects haemostasis