Kuvan Side Effects

Generic Name: sapropterin

Note: This document contains side effect information about sapropterin. Some of the dosage forms listed on this page may not apply to the brand name Kuvan.

Some side effects of Kuvan may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

For the Consumer

Applies to sapropterin: oral powder for solution, oral tablet disintegrating

Along with its needed effects, sapropterin (the active ingredient contained in Kuvan) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking sapropterin:

More common
  • Fever
Incidence not known
  • Burning feeling in the chest or stomach
  • cough
  • difficulty swallowing
  • dizziness
  • fast heartbeat
  • fidgeting or moving around too much
  • indigestion
  • puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • skin rash, hives, or itching
  • stomach upset
  • talking too much
  • tenderness in the stomach area
  • tightness in the chest
  • unusual tiredness or weakness

Some side effects of sapropterin may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common
  • Diarrhea
  • headache
  • runny nose
  • sore throat
  • vomiting
Less common
  • Stuffy nose

For Healthcare Professionals

Applies to sapropterin: oral tablet dispersible

Nervous system

Very common (10% or more): Headache (15%)
Common (1% to 10%): Dizziness
Frequency not reported: Convulsions, exacerbation of convulsions, overstimulation
Postmarketing reports: Hyperactivity (at least 2 cases)


Very common (10% or more): Rhinorrhea (11%), pharyngolaryngeal pain (10%)
Common (1% to 10%): Cough (7%), nasal congestion (4%), pharyngitis, upper respiratory tract infection
Frequency not reported: Respiratory failure
Postmarketing reports: Pharyngitis


Common (1% to 10%): Diarrhea (8%), vomiting (8%), nausea, abdominal pain, upper abdominal pain
Frequency not reported: Gastrointestinal bleeding
Postmarketing reports: Oropharyngeal pain, esophageal pain, gastritis, dyspepsia, abdominal pain, nausea, vomiting


Frequency not reported: Myocardial infarction


Common (1% to 10%): Peripheral edema
Frequency not reported: Contusion, postprocedural bleeding, pyrexia


Common (1% to 10%): Agitation
Frequency not reported: Irritability


Common (1% to 10%): Arthralgia


Common (1% to 10%): Polyuria


Postmarketing reports: Hypersensitivity reactions (including anaphylaxis and rash)


Frequency not reported: Rash


Frequency not reported: Increased gamma-glutamyltransferase (at least 2 cases)

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