1 What is Kuvan?

Brand: Kuvan

Generic: Sapropterin

Kuvan is used to treat patients with a genetic condition called phenylketonuria (PKU).

Phenylketonuria happens when the body is unable to metabolize the amino acid phenylalanine due to the absence of activity of phenylalanine hydroxylase (PAH). This allows phenylalanine to build up in the body, causing toxicities to the brain resulting in intellectual deficits, seizures and severe learning disabilities as the child grows older.

Current medical treatment for phenylketonuria is early detection (via newborn screening) and diet low in phenylalanine. Sapropterin works by lowering levels of phenylalanine in the bloodstream. Sapropterin is a synthetic form of cofactor BH4, which activates PAH in the body. This enables Sapropterin to reduce phenylalanine levels, and it must be used along with low-phenylalanine diet.

Note that not all cases of phenylketonuria respond to Sapropterin. Estimates show that Sapropterin only works for 25% to 50% of phenylketonuria patients.

Sapropterin is a prescription drug and must be used only according to doctor’s instructions.

Have a question aboutPhenylketonuria?Ask a doctor now

2 What to know before using

Before using Kuvan, you must know all about the risks and complications associated with it.

Do not receive Sapropterin if you are allergic to it. If you experienced allergies to Sapropterin before, tell it to your doctor before treatment.

Before receiving Sapropterin, tell the doctor all of your health problems. The doctor need to know if you have the following health problems before prescribing Sapropterin:

  • Liver disease
  • Kidney disease
  • History of ulcers or bleeding in the stomach
  • History or presently having cancer
  • Having little or no appetite
  • If you are malnourished

Tell your doctor if you are pregnant or breastfeeding before taking Sapropterin. Sapropterin is not proven completely safe for the unborn baby when used by pregnant patients. Sapropterin may also be expressed in breast milk, so do not breastfeed while taking it.

The safety and effectiveness of Sapropterin in one-month old children are still not fully known.

Sapropterin should be used very carefully in children. Sapropterin can cause phenylalanine levels to become too low and cause serious symptoms. Do not use Sapropterin without doctor’s instructions.

3 Proper usage

To use Kuvan properly, you must follow all instructions given by your doctor.

Sapropterin is available in tablets or powder that you take by mouth. Sapropterin comes with an information guide. Make sure you read and understand the information in this guide before using Sapropterin. If you have questions, ask your doctor or pharmacist.

The doctor will determine your dose of Sapropterin and will give you instructions on how to use it. Sapropterin is taken by mouth and usually taken once a day.

Sapropterin works within 24 hours, but it needs 30 days for it to take full effect. Only use Sapropterin as directed by the doctor. Take Sapropterin at the same time everyday.

The dose of Sapropterin is based on weight, so you need to weigh the child regularly and report changes to the doctor.

Taking Sapropterin with food helps improve absorption. Sapropterin tablets can be swallowed whole or dissolved in 4 oz. to 8 oz. of water or apple juice. Here are some important things to remember when dissolving

Sapropterin tablets:

  • Sapropterin tablets can be crushed and mixed with small quantities of soft foods like puddings or applesauce.
  • It will take few minutes for Sapropterin tablets to dissolve in liquids, and there may be small pieces still left. These pieces can be swallowed safely.
  • The liquid with dissolved Sapropterin must be taken within 15 minutes after preparation. Make sure to stir before drinking.
  • After drinking the dissolved Sapropterin tablets, wash the sides of the same glass with little water, swirl, and drink right away to get the entire dose.
  • Sapropterin powders can be dissolved in 4 oz. to 8 oz. apple juice or water. Here are some important things to remember in using Sapropterin powder:
  • If giving the medicine to small children, Sapropterin powder can be dissolved in one teaspoon water or apple juice. The liquid is aspirated and given to the child using an oral dosing syringe. You can ask the pharmacist to give you an oral dosing syringe.
  • Dissolved Sapropterin powder must be stirred before drinking. The prepared liquid must be taken within 30 minutes after preparation.
  • Sapropterin powder can also be dissolved in apple sauce or puddings.

The doctor will adjust the dose of Sapropterin over time depending on body’s response. The doctor may change the dose of Sapropterin as the child becomes older. The doctor will order regular blood tests to determine if Sapropterin is working.

Note that you still have to stick to a low-phenylalanine diet while receiving Sapropterin. The doctor or nutrition counselor will create a diet plan. Make sure to familiarize yourself with the diet plan.

If you missed a dose of Sapropterin, take it as soon as you remember. If it is almost time for the next dose, skip the missed dose and stick to regular dose. Do not take two doses at once or increase the dose to make up for the missed dose.

Keep Sapropterin tablets and powders away from children’s reach. Taking too much Sapropterin can cause an overdose. If this happens, call local poison control hotlines for medical assistance.

Keep Sapropterin at room temperature away from light, moisture and heat.

4 Precautions to take

Before using Kuvan, there are some precautions you must take.

Make sure to stick to lab tests when receiving Sapropterin. A blood test is the only way the doctor will know if Sapropterin is working.

Keep Sapropterin out of reach of children to avoid overdose.

Sapropterin will work only for phenylketonuria if the patient sticks to the low-phenylalanine diet. Follow doctor’s instructions and diet plan accordingly.

5 Potential side effects

As with many medications, there are several potential side effects associated with Kuvan.

Call the doctor if the patient experiences the following symptoms while receiving Sapropterin:

  • A Severe allergic reaction such as hives, skin rash, itching, wheezing, difficulty breathing, swelling of the tongue, mouth, lips or throat.
  • Symptoms that Sapropterin is not working properly, such as behavior changes, numbness, tingling, problems with vision, speech or balance.
  • Heartburn or indigestion
  • Severe stomach pain
  • Nausea and vomiting
  • Passing out bloody or tarry stools
  • Coughing up gross blood or substance that looks like coffee grounds
  • Hyperactive behavior
  • Convulsions
  • Chest pain or pressure, or pain that spreads to the jaw or shoulder

Sapropterin may cause common side effects such as:

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