This longitudinal study tests the hypothesis that obesity affects drug pharmacology of acid suppression medications in children.

The purpose of this research study is to see how the body breaks down certain medicines. Many medicines are broken down in the liver. The liver is an organ in the belly. A person's age, size, genetics (DNA), and the health of their liver decide how quickly the body breaks down medicines and how much medication a person needs to take. Everybody's liver has some fat in it, but the amount of fat is different from person to person. The purpose of this study is to see if the amount of fat in the liver affects how quickly acid suppression medications start and stop working and get removed from the body.

Inclusion Criteria:

• 6-21 years of age

• Obese and non-obese individuals

  • BMI ≥10th percentile for age (6-20 years of age)
  • BMI ≥18.5 (>20 years of age)

• Otherwise healthy; or otherwise healthy with diagnosis of GERD, NAFLD, chronic abdominal pain or obesity, according to report of medical history and/or review of the medical record

• Receiving or not receiving pantoprazole or lansoprazole for routine medical care

• MRI Hoop Test Clearance

Exclusion Criteria:

• Unable or unwilling to give written permission/assent/consent
• For PO Study Drug: Any anatomic abnormality of the GI tract as defined by history, PE, or radiographic findings, including Bariatric surgery, Nissen fundoplication or equivalent surgery.
• For IV Study Drug: Any anatomic abnormality of the GI tract as defined by history, PE, or radiographic findings, except Bariatric surgery, Nissen fundoplication or equivalent surgery.
• For subjects undergoing weight management, treatment in the last 7 days with proton pump inhibitors omeprazole, esomeprazole, dexlansoprazole, or grapefruit juice.
• For subjects not undergoing weight management, treatment in the last 7 days with medications known to clinically significantly inhibit (e.g., omeprazole, esomeprazole, fluoxetine, fluvoxamine, ketoconazole, ticlopidine, felbamate, trazodone, valproic acid, topiramate) or induce (e.g., phenobarbital, carbamazepine, phenytoin) CYP2C19; and those known at therapeutic doses to significantly inhibit (e.g., erythromycin, clarithromycin, grapefruit juice, verapamil, diltiazem, cimetidine, ketoconazole) or induce (e.g., oxcarbazepine, carbamazepine, phenytoin, phenobarbital, St. John's Wort, rifampin, rifapentine) or CYP3A4 activity in the last 7 days.
• Unable to have blood drawn for the screening lab tests
• Unable or unwilling to fast overnight prior to the study session
• Unable to have blood drawn for the screening lab tests
• If taking lansoprazole or pantoprazole for clinical purposes, unable or unwilling to abstain from that PPI for 3 days prior to PK visit when the PPI is not the same as the study drug for that PK visit
• Metal in the body or any foreign bodies that precludes MRI sequencing
• Claustrophobia
• Exceeds 500lbs or 227 kg in Body Weight
• Demonstrated adverse reaction to previous pantoprazole or PPI exposure
• Impaired hepatic activity as determined by routine liver function testing and defined as values ≥ 5 times the age-specific upper limit of normal (ULN) for AST, ALT, total bilirubin >2.0mg/dl, alkaline phosphatase ≥ 5 times the age-specific ULN
• Impaired renal function defined as creatinine ≥ 3 times the age-specific ULN
• Females of child-bearing age who are pregnant or breast-feeding
• Any known infection with hepatitis B, C, or human immunodeficiency virus (HIV)

Deidentified experimental data may be shared with institutional collaborators outside of CMH and if it is determined that biological samples obtained from study participants must be transferred to institutions outside of CMH for the purpose of confirmatory analyses, appropriate inter-institutional material transfer agreements will first be executed. As this is a pediatric study, minimal blood volumes are being collected and we do not anticipate that biological samples will be available to share with the outside community upon completion of the study, beyond those samples that may be required for confirmatory analyses.

76 participants enrolled to receive PPI study drug(s): 48 received lansoprazole (43 also received pantoprazole, 9 also received midazolam) 71 received pantoprazole (43 also received lansoprazole, 29 also received midazolam) 29 received midazolam (29 also received pantoprazole, and 9 also received lansoprazole)

From enrollment until end of pharmacokinetic study visit day, up to 24 hours

Subjects and their parents were monitored during their study visit with direct access to study personnel, and they provided with contact numbers to enable them to contact an investigator 24 hours daily in the event of an adverse effect following the study visit.

Although our population model is based on a relatively small sample size (n=40), it is the only published model of PPI PK for obese children. Model-derived PK parameters were substantially different from those previously reported for non-obese children, who were not included in this study, as the study objective was to describe pantoprazole PK specifically for obese children.