Valproic Acid-associated Hypoalbuminemia in Medically Fragile Patients
The purpose of this study is to investigate potential mechanisms of valproic acid-associated low serum albumin in medically fragile pediatric and young adult epileptic patients of a long-term care facility.
|Study Design:||Observational Model: Case Control|
|Official Title:||Valproic Acid-associated Hypoalbuminemia in Medically Fragile Pediatric and Young Adult Patients in a Long Term Care Facility Part 1: Potential Mechanism for Decreased Albumin Synthesis|
- The primary outcome will be serum albumin concentrations at baseline in the patients receiving VPA. [ Time Frame: Baseline ] [ Designated as safety issue: Yes ]
- Secondary outcome variables will include serum amino acid concentrations, total protein, AST, ALT, alkaline phosphatase, ammonia, BUN, and sCr and urine albumin, protein, and urea. [ Time Frame: Baseline ] [ Designated as safety issue: No ]
Biospecimen Retention: Samples Without DNA
Serum and urine samples from patients receiving VPA.
|Study Start Date:||February 2009|
|Study Completion Date:||December 2010|
|Primary Completion Date:||December 2009 (Final data collection date for primary outcome measure)|
Resident of Hattie Larlham long-term care facility receiving VPA
Procedure: Specimen collection
A blood sample and a spot urine sample will be obtained from all eligible patients receiving VPA at the start of the study.
Control AED patients will be recruited based on similar AED regimens excluding VPA, length of time on AED (number of months to >1 year), age, and gender; one control patient per VPA patient.
Control non-AED patients will be recruited based on age and gender; one control patient per VPA patient.
Valproic acid (VPA) is a long-chain fatty acid frequently used as an antiepileptic agent in pediatric and adult seizure patients. Other adverse effects that have been associated with VPA use include hepatic steatosis, altered mitochondrial function and decreased concentrations of serum proteins. The exact mechanism or mechanisms by which VPA induces these associated adverse drug effects are not fully understood though multiple theories have been postulated including impaired vesicle transport within the hepatocyte, inhibition of hepatic synthetic metabolic pathways and renal protein loss. Decreased serum albumin concentrations with concomitant VPA use have been identified in multiple studies. Albumin synthesis is sensitive to tryptophan concentrations (other amino acids are also able to stimulate albumin synthesis), oncotic pressure near the synthetic site, and energy supply while albumin release from the hepatocyte is sensitive to intrahepatocellular potassium concentrations. Based on available literature, VPA appears to inhibit an enzyme(s) either directly or indirectly involved with albumin synthesis or albumin gene expression. VPA is known to inhibit the urea cycle, including patients with ornithine-transcarbamylase (OTC) deficiency, possibly by inhibiting mitochondrial carbamoyl-phosphate synthase. Oratz et al discussed the potential correlation between the urea cycle and albumin synthesis identified after the administration of various amino acids increased both albumin and urea synthesis. Ornithine is an intermediate amino acid within the urea cycle and it is also a precursor to polyamines which have been shown to increase the degree of aggregation of polysomes, responsible for protein synthesis, bound to the endoplasmic reticulum. Thus, VPA may indirectly inhibit protein synthesis by interfering with the urea cycle leading to decreased ornithine concentrations and subsequently a decrease in polyamine concentrations and a decrease in the number of bound polysomes resulting in alterations in albumin synthesis and release. The purpose of this study is to investigate potential mechanisms of VPA-associated hypoalbuminemia in medically fragile pediatric and young adult epileptic patients of a long-term care facility.
|United States, Ohio|
|Hattie Larlham Center for Children with Disabilities|
|Mantua, Ohio, United States, 44255|
|Principal Investigator:||Michael Reed, PharmD||Akron Children's Hospital Research Center|
|Study Chair:||Martha Blackford, PharmD||Akron Children's Hospital|
|Study Chair:||Richard Grossberg, MD||Hattie Larlham|