History of intracranial hemorrhage. History of cerebrovascular disease, intracranial surgery or head trauma <3 months. Digestive or urinary bleeding <21 days. Recent surgery <14 days. Recent serious trauma <4 weeks. Puncture of major vessels no compressible in the last 7 days. Thrombin time > 20 seconds or a coagulation time > 10 seconds. Treatment with anticoagulant pharmaceuticals. Active internal bleeding (<3 weeks) or other conditions where there is significant risk of bleeding or would be difficult to manage because of its location. Hemorrhoidal disease caused by portal hypertension. Hemorrhoidal disease associated with abscess, fistula or cancer. Hemorrhoidal disease with septic complications or active hemorrhage. Administration of Streptokinase in the preceding 6 months. History of allergy to Streptokinase, Thiomersal or Salicylates (including aspirin), or any ingredient of the formulations under study. Pregnancy or lactation. Obvious mental incapacity to give consent, and act accordingly to the study.