Dosage and formulation issues: oral vitamin E therapy in children.
OBJECTIVE
Oral vitamin E is used in several childhood diseases, but dosage recommendations differ. Few oral products have a marketing authorization for therapeutic use in children. Preliminary data indicate differences in bioavailability among the various vitamin E compounds. Our objective was to review published data on oral vitamin E therapy in neonates and children in order to establish dosage recommendations at a local level.


METHODS
A literature search was conducted, including Medline Ovid, EMBASE (1980-Feb 2008), Cochrane databases, product monographs, handbooks, and textbooks.


RESULTS
The main vitamin E compounds being used in children are alpha-tocopherol, alpha-tocopheryl acetate, and tocofersolan. The most data are available on tocopheryl acetate, both in neonates and older children. In children with malabsorption disorders, tocofersolan appears to have an increased bioavailability compared to tocopherol or tocopheryl acetate. Published data on pharmacokinetics and dosages for clinical use are few and heterogeneous. No pharmacokinetic studies were found for tocofersolan in neonates and infants. There are few comparative studies on pharmacokinetics, therapeutic use, and adverse drug reactions (ADRs) in children. Dosages used in clinical studies and dosage recommendations in handbooks differ considerably.


CONCLUSIONS
The differences in dosing recommendations in children may be due to lack of systematic studies. Existing published data on oral vitamin E do not provide a basis for evaluation of dosage recommendations in children. Comparative clinical studies are required for scientific evaluation of pharmacokinetics, dosage regimens, and efficacy/ADR assessments in children.
Westergren
Tone
T
RELIS, Regional Medicines Information Center, Oslo University Hospital, Rikshospitalet, Oslo, Norway. tone.westergren@rikshospitalet.no
Kalikstad
Betty
B
D000284:Administration, Oral; D000293:Adolescent; D002626:Chemistry, Pharmaceutical; D002648:Child; D002675:Child, Preschool; D002986:Clinical Trials as Topic; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D017410:Practice Guidelines as Topic; D014810:Vitamin E / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics / Q000627:therapeutic use*
D014810:Vitamin E