• Plasma morphine and codeine concentrations
  
• CYP2D6 genotype
  

• Disease severity
  
• Hospitalizations and admissions
  

People with sickle cell disease require oral pain medications to manage an acute pain crisis. Sometimes these individuals fail to obtain adequate pain relief with the medications prescribed for outpatient use resulting in emergency room visits and hospital admissions. Subsequently, many patients are admitted to the hospital for pain management for a few days until the pain crisis resolves. The most common medications prescribed to sickle cell individuals for outpatient use include codeine and hydrocodone containing medications (i.e. Tylenol #3™, Vicodin™, Lortab™). These medications must be broken down in the body to make the active pain reliever (morphine or hydromorphone, respectively). Some individuals may not be able to break down these medications to the active pain reliever; therefore, these individuals will likely continue to experience pain unless they take other pain medications. We will determine whether genotype estimates the ability of CYP2D6 to break down codeine to the active pain reliever in individuals with sickle cell disease.