Inclusion Criteria:  Diagnosis of acute pancreatitis confirmed by revised Atlanta criteria Admitted to the medical floor within 48 hours of emergency department arrival at Beth Israel Deaconess Medical Center (BIDMC) in Boston, Massachusetts. Age 18-65  Exclusion Criteria:  Active illicit drug use Discharged from the emergency department Direct admission to ICU from emergency department Known allergy to opioid medications Age <18 or >65 Known chronic pain syndrome or concurrent other medical condition with chronic pain Active encephalopathy/confusion/delirium/psychiatric illness or any other condition that limits capacity Known chronic opioid use Renal insufficiency (baseline Creatinine of >2 and/or acute kidney injury with Creatinine>3 on admission) Known allergy to acetaminophen or hepatic dysfunction otherwise limiting acetaminophen use