title: Adherence to tetrahydrobiopterin therapy in patients with phenylketonuria.
abstract: Phenylketonuria (PKU) is an inborn error in phenylalanine metabolism due to deficiency of the enzyme, phenylalanine hydroxylase (PAH). Treatment includes restriction of dietary phenylalanine, and in some individuals, supplementation with the PAH cofactor, tetrahydrobiopterin (sapropterin dihydrochloride). A survey was conducted among patients with PKU who had been prescribed sapropterin to assess reasons for continuing or discontinuing the drug. The primary reason that sapropterin responders discontinued the drug was because of side effects, followed by insufficient reduction of blood phenylalanine and insurance issues. Conversely, those who remained on therapy cited increased tolerance for dietary protein as the main reason for continuation, along with lower blood phenylalanine concentrations and feeling better. This study suggests that adherence to sapropterin therapy is mainly dependent upon the increase in dietary protein allowed when on the drug.
authors.affiliation: Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, USA. Electronic address: frances.rohr@childrens.harvard.edu.
authors.forename: Frances
authors.initials: F
authors.lastname: Rohr
authors.affiliation: Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, USA.
authors.forename: Ann
authors.initials: A
authors.lastname: Wessel
authors.affiliation: Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Brown
authors.affiliation: Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, USA.
authors.forename: Kalin
authors.initials: K
authors.lastname: Charette
authors.affiliation: Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, USA.
authors.forename: Harvey L
authors.initials: HL
authors.lastname: Levy
mesh_terms: D000293:Adolescent; D000328:Adult; D001708:Biopterins / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D003625:Data Collection; D004032:Diet; D004044:Dietary Proteins / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D010649:Phenylalanine / Q000097:blood*; D010661:Phenylketonurias / Q000097:blood / Q000628:therapy*; D013689:Telephone; D055815:Young Adult
chemical_list: D004044:Dietary Proteins; D001708:Biopterins; D010649:Phenylalanine; C003402:sapropterin
keywords: Adherence; BH4; Kuvan; Phenylketonuria; Sapropterin dihydrochloride