Skip to main content


Generic name: sodium phenylbutyrateSOW-dee-um-fen-il-BYOO-ti-rate ]
Brand names: Buphenyl, Olpruva, Pheburane
Drug class: Urea cycle disorder agents

Medically reviewed by on Jul 21, 2023. Written by Cerner Multum.

What is Buphenyl?

Buphenyl is used in adults and children to treat urea cycle disorders.

Buphenyl can be used with other medicines and may also include changes in diet.

Buphenyl may also be used for purposes not listed in this medication guide.

Buphenyl side effects

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

Buphenyl may cause serious side effects. Call your doctor at once if you have:

Common side effects of Buphenyl may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


Use only as directed. Tell your doctor if you use other medicines or have other medical conditions or allergies.

Before taking this medicine

Buphenyl should not be used to treat immediate symptoms of an ammonia build-up.

Tell your doctor if you have:

Tell your doctor if you are pregnant or breastfeeding.

How should I take Buphenyl?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.

You may need to follow a special diet. Follow all instructions of your doctor or dietitian. Learn about the foods you should eat or avoid.

Wear a medical alert tag or carry an ID card to let others know you have a urea cycle disorder.

Doses are based on weight. Your dose may change if you gain or lose weight.

Take Buphenyl with food.

Shake the oral powder lightly before mixing it with food.

Measure the dose of sodium phenylbutyrate oral pellets with the supplied measuring device (not a kitchen spoon).

Swallow Buphenyl oral pellets immediately with soft food, such as applesauce, or water, fruit juices, or protein-free infant formulas. Do not chew or mix into liquids.

Do not give or take Buphenyl oral suspension and oral pellets through a gastrostomy or nasogastric tube

Your blood may need to be tested often.

Store at room temperature away from moisture and heat. Keep the bottle tightly closed when not in use. Throw away any remaining oral pellets 45 days after first opening the bottle.

What happens if I miss a dose?

Oral pellet: Use the medicine as soon as you can, but skip the missed dose if your next dose is due in less than 3 hours. Do not use two doses at one time.

Oral suspension, tablets, powder: Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking Buphenyl?

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

What other drugs will affect Buphenyl?

Tell your doctor about all your other medicines, especially:

This list is not complete. Other drugs may affect Buphenyl, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.