Sapropterin dihydrochloride: a new drug and a new concept in the management of phenylketonuria.
Phenylketonuria (PKU) is characterized by persistent hyperphenylalaninemia, due to mutations in the gene coding for phenylalanine hydroxylase (PAH). If untreated, patients develop profound mental retardation. The principal treatment for PKU is lifelong dietary phenylalanine restriction, requiring the administration of special phenylalanine-free protein supplements. Adhering to the diet is burdensome, and poor compliance and control of blood phenylalanine are common, especially in adolescents and adults. A subset of patients, particularly those with milder forms of PKU, shows a clinically significant reduction in blood phenylalanine when treated with pharmacological doses of tetrahydrobiopterin, the cofactor of PAH. A tablet formulation of sapropterin dihydrochloride is approved for therapeutic use in Europe and the USA. Clinical trials have demonstrated durable reductions in blood phenylalanine, and/or increased dietary phenylalanine tolerance, in some patients with hyperphenylalaninemia due to PKU. Although further data are needed, especially with regard to long-term neuropsychological outcomes or possible use in pregnancy, sapropterin appears to represent a useful addition to the management of PKU.
Trefz
F K
FK
Klinik fur Kinder und Jugendmedizin Reutlingen, Reutlingen, Germany. friedrich.trefz@gmx.de
Belanger-Quintana
A
A
D000284:Administration, Oral; D001708:Biopterins / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D019317:Evidence-Based Medicine; D006801:Humans; D010649:Phenylalanine / Q000378:metabolism; D010651:Phenylalanine Hydroxylase / Q000235:genetics / Q000378:metabolism; D010661:Phenylketonurias / Q000188:drug therapy* / Q000453:epidemiology / Q000235:genetics / Q000378:metabolism; D013607:Tablets; D016896:Treatment Outcome
D013607:Tablets; D001708:Biopterins; D010649:Phenylalanine; D010651:Phenylalanine Hydroxylase; C003402:sapropterin