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(sapropterin dihydrochloride) Tablets and Powder for Oral Solution


KUVAN (sapropterin dihydrochloride) is an orally administered Phenylalanine Hydroxylase activator (or PAH activator). Sapropterin dihydrochloride, the active pharmaceutical ingredient in Kuvan, is a synthetic preparation of the dihydrochloride salt of naturally occurring tetrahydrobiopterin (BH4). Sapropterin dihydrochloride is an off-white to light yellow crystals or crystalline powder.

The chemical name of sapropterin dihydrochloride is (6R)-2-amino-6-[(1R,2S)-1,2dihydroxypropyl]-5,6,7,8-tetrahydro-4(1H)-pteridinone dihydrochloride and the molecular formula is C9H15N5O3·2HCl with a molecular weight of 314.17.

Sapropterin dihydrochloride has the following structural formula:

KUVAN (sapropterin dihydrochloride) Structural Formula Illustration

Kuvan is supplied as tablets and powder for oral solution containing 100 mg of sapropterin dihydrochloride (equivalent to 76.8mg of sapropterin base).

Tablets are round, off-white to light yellow, mottled, and debossed with “177”. Each tablet contains the following inactive ingredients: ascorbic acid (USP), crospovidone (NF), dibasic calcium phosphate (USP), D-mannitol (USP), riboflavin (USP), and sodium stearyl fumarate (NF).

Kuvan powder for oral solution is off-white to yellow in color. Each unit dose packet contains the following inactive ingredients: ascorbic acid (USP), D-mannitol (USP), potassium citrate (USP), and sucralose (NF).

What are the possible side effects of sapropterin (Kuvan)?

If sapropterin is not controlling your condition properly, you may have symptoms such as behavior changes, numbness or tingling, or problems with speech, vision, or balance. Call your doctor right away if you have any of these symptoms.

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have any of the serious side effects below:

  • seizure (convulsions);
  • chest pain or heavy feeling, pain spreading to the arm or...

Read All Potential Side Effects and See Pictures of Kuvan »

Last reviewed on RxList: 1/6/2014
This monograph has been modified to include the generic and brand name in many instances.

Report Problems to the Food and Drug Administration


You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

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