The purpose of this study is to determine if the use of tranexamic acid prior adenotonsillectomy in children can reduce surgical and postoperative bleeding.

Tonsillectomy with or without adenoidectomy is the most common major surgical procedure performed in children. Although it's a relatively simple procedure, may present complications as hemorrhage and death. The mortality associated to the surgery range between 1/1.000 and 1/27.000 in the literature, with approximately 30% due to hemorrhage.

Tranexamic acid is an antifibrinolytic hemostatic indicated to control bleeding in cases of hyperfibrinolysis or defective hemostasis diseases. It's major indications are prostatic surgery and menorrhagia.

Inclusion Criteria:

• children with 4 to 12 years
• adenotonsillar hypertrophy
• indication of adenotonsillectomy

Exclusion Criteria:

• patients with blood dyscrasia
• patients with history of bleeding of difficult control or spontaneous hematoma
• patients with coagulation tests altered
• patients with evidence of hematopoietic, cardiovascular, hepatic, renal, neurologic, psychiatric or auto immune disease