What is it and how is it used?
Kuvan is a synthetic copy of a body’s own substance called tetrahydrobiopterin (BH4). BH4 is required by the body to use an amino acid called phenylalanine in order to build another amino acid called tyrosine.
Kuvan is used for the treatment of hyperphenylalaninaemia (HPA) or phenylketonuria (PKU), due to abnormally high levels of phenylalanine in the blood, which can be harmful. Kuvan reduces these levels in some patients who respond to BH4 and can help increase the amount of phenylalanine that can be included in the diet.
Kuvan is also used for the treatment of an inherited disease called BH4 deficiency, in which the body cannot produce enough BH4. Because of very low BH4 levels phenylalanine is not used properly and its levels rise, resulting in harmful effects. By replacing the BH4 that the body cannot produce, Kuvan reduces the harmful excess of phenylalanine in the blood and increases the dietary tolerance to phenylalanine.
What do you have to consider before using it?
Do not take KuvanIf you are allergic (hypersensitive) to sapropterin or any of the other ingredients of Kuvan.
Take special care with Kuvan
You should consult your doctor:
When you are treated with Kuvan, your doctor will test your blood to verify how much phenylalanine and tyrosine it contains and may decide to adjust the dose of Kuvan or your diet if needed.
You must continue your diet treatment as recommended by your doctor. Do not change your diet without contacting your doctor.
Taking other medicines
You should consult your doctor if you are taking:
Please tell your doctor or pharmacist if you are taking or have recently taken any other medicines, including medicines obtained without a prescription.
Taking Kuvan with food and drink
Kuvan should be taken with food at the same time each day preferably in the morning.
Pregnancy and breast-feeding
For Kuvan no information is available for human pregnancies. Animal studies do not indicate direct or indirect harmful effects with respect to pregnancy , embryonal/foetal development, birth or postnatal development.
If maternal phenylalanine levels are not strictly controlled before and during pregnancy, this could be harmful to the mother and the foetus. In case of pregnancy your doctor will tell you how to control phenylalanine levels adequately. Physician-supervised restriction of dietary phenylalanine intake prior to and throughout pregnancy is the first choice of treatment in this patient group.
The use of Kuvan should be considered only if strict dietary management does not adequately reduce blood phenylalanine levels.
Be sure to tell your doctor if you are pregnant or breast-feeding, if you think you might be pregnant, or if you are planning to become pregnant or are planning to begin breast-feeding.
You should not take Kuvan if you are breast-feeding.
Ask your doctor or pharmacist for advice before taking any medicine.
Driving and using machines
No studies on the effects on the ability to drive and use machines have been performed. Kuvan is not expected to affect the ability to drive and use machines.'
How is it used?
Always take Kuvan exactly as your doctor has told you. You should check with your doctor if you are not sure.
Dosage
PKU
The usual starting dose of Kuvan in adult and paediatric patients with PKU is 10 mg for each kg of body weight. Take the soluble tablets as a single daily dose with a meal to increase the absorption, and at the same time each day, preferably in the morning. Your doctor may adjust your dose, usually between 5 and 20 mg for each kg of body weight per day, depending on your condition.
BH4 deficiency
The usual starting dose of Kuvan in adult and paediatric patients with BH4 deficiency is 2 to 5 mg for each kg of body weight. Take the soluble tablets as a single daily dose, with a meal to increase the absorption, and at the same time each day, preferably in the morning. Your doctor may adjust your dose up to 20 mg for each kg of body weight per day, depending on your condition. It may be necessary to divide the total daily dose into 2 or 3 doses, distributed over the day, to achieve the best therapeutic effect.
The table below is an example of how an appropriate dose is calculated:

Method of Administration
Adults
Place the tablets in a glass or cup (120 to 240 ml) of water and stir until dissolved.
Paediatric patients
The prescribed number of tablets should be placed in a glass or cup (up to 120 ml) of water and stir until dissolved.
For doses below 100 mg, one tablet should be dissolved in 100 ml of water. Your doctor will tell you to administer only a certain volume of the solution corresponding to the appropriate dose. An accurate measuring device with suitable graduations should be used for this purpose.
It may take a few minutes for the tablets to dissolve. To make the tablets dissolve faster you can crush them. Small particles may be visible in the solution, but they will not affect the effectiveness of the medicine. Drink the dissolved preparation of Kuvan with a meal, at the same time each day, preferably in the morning within 15 to 20 minutes of its preparation.
Make sure you do not swallow the desiccant capsule contained in the bottle.
If you take more Kuvan than you should
If you take more Kuvan than prescribed, you may experience side effects that could include headache and dizziness. You should immediately contact your doctor or pharmacist if you take more Kuvan than prescribed.
If you forget to take Kuvan
Do not take a double dose to make up for a forgotten dose.
If you stop taking Kuvan
Do not stop taking Kuvan without prior discussion with your doctor, as phenylalanine levels in the blood may increase.
If you have any further questions on the use of this product, ask your doctor or pharmacist.
What are possible side effects?
Like all medicines, Kuvan can cause side effects, although not everybody gets them.
Frequencies of side effects are defined as:
Very common side effects: headache and runny nose.
Common side effects: sore throat, nasal congestion or stuffy nose, cough, diarrhoea, vomiting, stomach ache and too low levels of phenylalanine in blood tests.
If any of the side effects gets serious, or if you notice any side effects not listed in this leaflet, please tell your doctor or pharmacist.
How should it be stored?
Keep out of the reach and sight of children.
Do not use Kuvan after the expiry date which is stated on the bottle and the carton after “EXP”. The expiry date refers to the last day of that month.
Store below 25°C.
Keep the bottle tightly closed in order to protect from moisture.
Medicines should not be disposed of via wastewater or household waste. Ask your pharmacist how to dispose of medicines no longer required. These measures will help to protect the environment.