 We will enroll those patients that have received intracranial surgery and admitted to neurosurgical ICU. After obtaining the consent, we will give them prophylactic drugs for 7 days within 24 hours. They are randomly allocated to 2 groups. Group I: esomeprazole 40 mg qd from NG route or orally; Group II: famotidine 20 mg iv bolus q12h. We will monitor the following data: Glasgow coma scale, APACHE II score, CBC, CXR, stool character and OB test, NG aspirate. If clinical evidence of UGI bleeding occurs, endoscopy will be performed. We define the end point as overt bleeding, death or transfer out of ICU. We will compare the prevalence of UGI bleeding and nosocomial pneumonia in these 2 groups. 