IMProving DRug Dosing and Outcomes for Single VEntricle Patients With Fontan Associated Liver Disease

Exclusion Criteria

• •Pregnancy
• •Non-fasting
• •Non-removable metal in body or where magnetic resonance imaging (MRI) is considered unsafe
• •Sildenafil and/or Pravastatin therapy within last 2 months
• •History of underlying or laboratory evidence of underlying intestinal, metabolic, autoimmune, renal disease that can alter Sildenafil and Pravastatin disposition (absorption, metabolism, distribution, or clearance)
• •Pharmacotherapy that interacts with Sildenafil (cytochrome P450 3A4 and P450 3A5 (CYP3A4/5) inducers/inhibitors) and/or Pravastatin (organic anion transporting polypeptide (OATP1B1) inducers/inhibitors)
• •Inability to swallow a tablet
• •\>5X the age-specific upper limit of normal for aspartate aminotransferase (AST) and alanine aminotransferase (ALT), total and conjugated bilirubin
• •Diarrhea in the last 24 hours \*History of solid organ transplantation