DRUG THERAPY FOR PHENYLKETONURIA: Sapropterin Dihydrochloride

The most common treatment for phenylketonuria (PKU), which is a congenital genetic disorder, is diet therapy that limits the amount of protein and phenylalanine taken with foods. However, it is very difficult to comply with the diet, but as the age gets older, there are also problems with diet compliance. Because protein-restricted diet means that 80% of normal foods are completely prohibited.

The use of Sapropterin dihydrochloride, which is one of the treatment methods for patients with PKU, was approved by the American Food and Drug Administration (FDA) in 2007. In 2008, it started to be sold under license in Europe. In Turkey it can be purchased from pharmacies with a prescription since 2018.

What is Sapropterin, How Does It Work?

"Sapropterin di hydrochloride", "BH4", is the name of the substance required for the operation of the enzyme "FAH", which is restricted in PKU patients. In patients with PKU, this substance is either absent or inadequate. With drug treatment, this substance is provided to the body from the outside. Thus, it is aimed to increase the "restricted" enzyme activity in patients with PKU. When the enzyme activity is increased, the phenylalanine taken with food is used by the body, and the levels of phenylalanine in the blood are taken under control.

Does It Remove Sapropterin Diet Therapy?

Studies have found that Sapropterin dihydrochloride is safe to use with diet. Therefore, Sapropterin does not eliminate dietary treatment, but allows for more (at least twice) natural protein use in the diet, making it easier to apply the diet. According to clinical studies on children with PKU, Sapropterin increases the tolerance of phenylalanine by 20 to 30 mg / kg / day. This means that both adult and child PKU patients can consume daily diets, such as normal bread, flour, pasta, legumes and whole vegetables, without measuring their diet. Thus, the diet becomes easier to apply and the need for synthetic proteins decrease.

Who Can Use? Do All Patients Respond to Treatment?

Sapropterin can be used by adults and children over 4 years old. However, a little bit of “FAH” enzyme activity is required for Sapropterin dihydrochloride to work. Therefore, studies show that the success rate of Sapropterin is between 25% and 50%. Sapropterin is also used for patients with BH4 metabolism disorder. The dosage for use depends on whether the patient responds to treatment. The dose can be increased unless the patient responds to treatment.

Food Engineer