Kuvan

Sapropterin dihydrochloride, the active ingredient in Kuvan, is a tetrahydrobiopterin (BH4) analog presented as an oral tablet for oral use. It treats phenylketonuria (PKU) by lowering blood phenylalanine concentrations in patients with this inherited metabolic disorder.

GNH USA supplies Kuvan as a licensed, GDP‑compliant international pharmaceutical supplier serving hospitals, pharmacies and clinics worldwide.

Kuvan is used in the management of phenylketonuria, a hereditary disorder of phenylalanine metabolism. - Phenylketonuria (PKU): reduces blood phenylalanine concentrations, allowing a less restrictive diet and improved metabolic control. - BH4‑responsive PKU: enhances residual phenylalanine hydroxylase activity in patients who respond to tetrahydrobiopterin supplementation. - Maternal PKU: helps maintain target phenylalanine levels during pregnancy when used under specialist supervision.

Kuvan may be associated with several adverse reactions, which are categorized by frequency and severity.

Common Side Effects: - Headache - Nausea - Vomiting - Abdominal pain - Fatigue - Diarrhea

Serious or Rare Side Effects: - Allergic reaction (rash, itching, swelling) - Anaphylaxis - Seizures (rare) - Severe skin reactions such as Stevens‑Johnson syndrome

When prescribing Kuvan, clinicians should consider the following precautions to ensure safe use. - Dose adjustment: individualize based on regular blood phenylalanine monitoring. - Renal function: assess in patients with impaired kidney function, as excretion is renal. - Hepatic function: monitor liver enzymes in patients with known liver disease. - Pediatric use: initiate under specialist guidance, adjusting dose as the child grows. - Concomitant dietary changes: coordinate with dietitian to avoid excessive phenylalanine intake. - Store at ambient temperature below 25°C: keep in the original container, protect from moisture and light.

Kuvan can interact with other substances that affect phenylalanine metabolism or drug absorption.

Major Interactions (Avoid): - Phenylalanine‑rich protein supplements: may counteract the drug’s effect on blood phenylalanine levels. - L‑phenylalanine medications: can increase phenylalanine load and reduce therapeutic benefit. - High‑dose vitamin C: may alter BH4 stability and diminish efficacy.

Moderate Interactions (Monitor Closely): - Antiepileptic drugs (e.g., carbamazepine, phenytoin): may affect sapropterin metabolism. - Oral contraceptives: potential to modify phenylalanine concentrations, requiring closer monitoring. - Antibiotics such as sulfonamides: may interfere with folate pathways linked to BH4 metabolism.