 1. Primary variables: incidence of upper or lower gastrointestinal bleeding in the follow-up period in both groups. Acute gastrointestinal bleeding it will be recorded, when they occur, at any time during the monitoring period. Is defined as any acute gastrointestinal bleeding episode in which medical care personnel finds the presence of macroscopic signs of bleeding hematemesis, rectal bleeding, hematochezia and or melena. Serious Gastrointestinal bleeding is defined as one that also present hemodynamic repercussion systolic blood pressure 100 mm Hg and heart rate 100 bpm or hemoglobin Hb 80 g l decrease in Hb 20 g l in 24 hours. 