Developmental Regulation of Proteins Responsible for Transforming Drugs in the Body

Inclusion Criteria

• Healthy children 12 months of age at enrollment

Exclusion Criteria

• Height and weight ratio outside of the 5th to 100th percentile for adjusted age
• Historical and/or biochemical evidence of hepatic, renal, or hematopoetic dysfunction
• Historical or physical evidence of a neurologic disease/condition (excluding simple, febrile seizures)
• Historical or physical evidence of any disorder associated with swallowing and/or gastrointestinal function
• Concomitant therapy with drugs or other products known to alter the activity of hepatic or intestinal microsomal enzymes(e.g., inducers or inhibitors of CYPs 1A2, 2D6, and/or 3A4), P-glycoprotein or potential competing substrates for the CYPs, under study within 7 days of a scheduled phenotyping evaluation
• Evidence of behavioral, developmental, or psychosocial conditions in the subjects and/or parents/caregivers that, in the opinion of the investigator, would have the potential to adversely impact the level of compliance required for successful study completion
• Evidence of geographic instability (i.e., moving of primary residence within last 24 months) that would adversely influence compliance with repeated study visits necessary for completion of the protocol
• Lack of telephone access required to insure adequate subject contact/follow-up
• Inability to obtain written informed consent from the subject's parents/guardians