Results for the substance sepiapterin

Sepiapterin is a medicine used for certain forms of phenylketonuria, a genetic condition in which the body cannot process phenylalanine properly. Phenylalanine is an amino acid found in protein foods; high levels can affect the brain and development. Sepiapterin is a precursor of the BH4 cofactor and may help lower blood phenylalanine levels.

It is taken by mouth as an oral powder once daily with food, at a dose calculated according to age and body weight. It must be used together with a phenylalanine-restricted diet, not as a replacement for diet. Response is checked through repeated blood phenylalanine tests and regular review of protein and phenylalanine intake.

Common side effects include diarrhoea, headache, abdominal pain, throat pain and yellow or orange stool discoloration. Blood phenylalanine can become too low, which may require diet or dose adjustment. Sepiapterin may also increase bleeding risk; tell your doctor about unusual bruising, red or purple skin marks, bleeding that lasts longer than usual or much heavier periods.

Treatment should be supervised by clinicians experienced in phenylketonuria, especially for infants and children, because growth, nutrition and blood levels must be balanced carefully. Tell your doctor about levodopa, blood-pressure medicines and products that may affect blood vessels. Do not change the diet or dose on your own, as high and low phenylalanine levels can be harmful.