Kuvan

Dosage and Administration

Kuvan medicine comes in the form of tablets and the state of powder for oral suspension. Tablets come in the strength of 100 mg and oral suspension in 100 mg and 500 mg. The powder and tablets are off-white to yellow.

Administration

Dosage administration of medicine to the patient should always be according to the prescription prescribed by the physician.

Patients with PKU who are treated with bh4 supplement should also be treated with a Phe Restricted diet, with dietary protein and Phe restriction.

Starting Dosage

In the case of pediatric patients (1 month to 6 years): The recommended starting dose of the medicine is 10 mg/kg once a day.
In the case of adult patients: Take the recommended starting dose of Kuvan as 10 to 20 mg/kg once a day.

Dosage adjustment

• If starting dose is 10 mg/kg per day, then the response to therapy is calculated by a change in blood Phe following treatment with the medicine at 10 mg/kg per day for a time interval of up to 1 month. Physicians should check blood Phe levels after 1 week of Kuvan treatment and at equal time intervals for a month. If blood Phe does not reduce from baseline at 10 mg/kg per day, one can increase the dose to 20 mg/kg per day. Discontinue the administration of medicine in patients whose blood Phe does not reduce after 1 month of treatment at 20 mg/kg every day do not show a biochemical response and treatment with Kuvan.
• If the starting dose is 20 mg/kg per day, one should calculate the response to therapy by a change in blood Phe after treatment with Kuvan at 20 mg/kg per day for 1 month. Check blood Phe levels after 1 week of treatment with the medicine and at equal intervals during the first month. Discontinue the treatment in patients who do not show a biochemical response after 1 month of treatment.
• Once the patient achieves responsiveness to Kuvan, adjust the dosage within the range of 5-20 mg/kg each day according to biochemical response to therapy. Professionals recommend periodic blood Phe to assess blood Phe control, especially in pediatric patients.

Instructions for preparation of dosages

Take Kuvan 100 mg orally with a meal, preferably at the same time each day. Professionals advise taking a missed dose as soon as possible, but do not take two doses on the same day.

Kuvan Tablets
Professionals advise against swallowing Kuvan tablets either as whole tablets or dissolve in 120 to 240 mL of liquid (water or apple juice) and take orally within 15 minutes of dissolution. The tablets may not dissolve completely. Patients may see small pieces of tablet floating on top of the water or apple juice. It is normal and safe for patients to swallow the medicine. If there are residuals of the tablet left after drinking the mixture, add more liquid to ensure that the patient has consumed all the drug. One can crush Kuvan tablets and then mix in a small quantity of soft foods such as applesauce or pudding.

Kuvan oral suspension
In patients weighing more than 10 kg:
Dissolve the Sapropterin powder for oral solution in 120 to 240 mL of liquid (water or apple juice) and take it orally within 30 minutes of dissolution. One can stir Kuvan powder for oral solution in a small amount of soft foods such as applesauce. Empty the contents of the packet in the liquid or a small amount of soft food and mix thoroughly. The powder should dissolve completely.

In patients weighing less than 10 kg or 10 kg:
One can dissolve the powder for oral solution in as little as 5 mL of the liquid and administer a portion of this solution corresponding to a 10 mg/kg dose orally through an oral dosing syringe.

Overdosage
If the patient takes an overdose there will be minor side effects like mild headache, mild dizziness or abdominal pain. Professional advice to discontinue the treatment until symptoms go away. And one can start the treatment again under healthcare professional’s supervision.

Side effects

The side effects of taking tetrahydrobiopterin supplement are categorized as:

Common
Nausea, headache, peripheral edema, arthralgia, polyuria, agitation, dizziness, pharyngitis, abdominal pain, upper abdominal pain, and upper respiratory tract infection are common side effects of the medicine.

Uncommon
Seizures, exacerbation of seizures, dizziness, gastrointestinal bleeding, post-procedural bleeding, headache, irritability, myocardial infarction, and overstimulation are uncommon side effects.

Rare
Nasal congestion or respiratory failure are rare known side effects of this medicine.

Precautions and Warnings

Patients with Hypersensitivity reactions
Professionals do not recommend Kuvan in patients with a history of anaphylaxis to bh4 supplement. According to clinical studies, Hypersensitivity reactions, including anaphylaxis and rash, have occurred. Discontinue treatment with this medicine in patients who experience anaphylaxis and start the proper medical treatment. Continue the dietary protein and Phe restriction in patients who experience anaphylaxis.

Patients are suffering from Upper Gastrointestinal Mucosal Inflammation.
There are reports on Gastrointestinal (GI) adverse reactions suggestive of upper GI mucosal inflammation with Kuvan. Serious reactions include esophagitis and gastritis. If GI mucosal inflammation is left untreated, these could lead to severe reactions, including esophageal stricture, esophageal ulcer, gastric ulcer, bleeding, and such complications. Professional advice to monitor patients for signs and symptoms of upper GI mucosal inflammation.

Patients experienced Hypo phenylalaninemia
Some patients experience hypo phenylalaninemia (low blood Phe) during treatment with this medicine. In a clinical study of pediatric patients treated with 20 mg/kg per day, the incidence of hypo phenylalaninemia was higher than in older patients.

Monitoring Blood Phe Levels
Long time elevations of blood Phe levels in patients with PKU can result in severe neurologic damage, including serious intellectual disability, developmental delay, microcephaly, delayed speech, seizures, and behavioral abnormalities. Active management of dietary Phe consumption while taking Sapropterin dihydrochloride is required to ensure adequate Phe control and nutritional balance. One should monitor blood Phe levels during treatment to ensure the proper blood Phe level control. Professionals recommend frequent monitoring of pediatric patients.

Administration in combination with Levodopa
Based on a 10-year post-marketing safety surveillance program for a non-PKU indication using another sapropterin product, 3 patients with underlying neurological disorders experienced seizures, over-stimulation, and irritability while administering Levodopa with sapropterin. One should monitor patients who are receiving Levodopa for changes in neurological status during treatment with this medicine.

Handling and storage

In the form of tablets
Kuvan Tablets 100 mg containing sapropterin dihydrochloride are round, off-white to light yellow, mottled, and debossed with “177”. This medicine comes in a bottle containing 120 tablets.

In the form of oral suspension

Supplied as an off-white to yellow powder in unit dose packets as:

• 100 mg of sapropterin dihydrochloride per packet:
• Carton of 30 unit dose packets.
• Single unit dose packet.

500 mg of sapropterin dihydrochloride per packet:
It comes in a carton of 30 unit dose packets.
Single unit dose packet.

• Store the tablets at 20ºC to 25ºC (68ºF to 77ºF); excursions are allowed between 15ºC-30ºC or 59ºF-86ºF.
• Keep the container tightly closed.
• Please protect it from moisture.

Store tetrahydrobiopterin medicine for an oral solution at 20ºC-25ºC or 68ºF-77ºF; excursions allowed between 15ºC-30ºC or 59ºF-86ºF.
Please protect it from moisture.