What is Sodium Phenylbutyrate: Uses, Warnings & Interactions

Updated May 14, 2025  •  Published Dec 30, 2020

Sodium Phenylbutyrate overview

BRAND NAMES:

  • Buphenyl

Generic Names:

  • Sodium Phenylbutyrate

Uses:

  • Treats urea cycle disorders to help remove nitrogen from the body.

Therapeutic Classes:

  • Hyperammonemia Agent, Nutritive Agent

Forms:

  • Powder, Tablet, Coated Tablet

How it’s taken:

  • By mouth

What is Sodium Phenylbutyrate used for?

Buphenyl comes in the form of an oral powder for reconstitution and is used for the long-term management of high levels of ammonia in the blood caused by urea cycle disorder. Buphenyl works by being converted in the body into a substance that helps the kidney eliminate waste and prevent ammonia build up. Common side effects may include loss of appetite, headaches and an unpleasant taste in your mouth.

What form(s) does Sodium Phenylbutyrate come in

  • Powder

  • Tablet

  • Coated Tablet

What are common Sodium Phenylbutyrate doses?

  • Bottle 250GM of 3GM/TSP

  • Bottle 250 Tablets

Common Sodium Phenylbutyrate prescriptions

  • Sodium Phenylbutyrate
    250 tablets bottle

  • Sodium Phenylbutyrate
    266gm of 3gm/tsp bottle

How to take Sodium Phenylbutyrate

  • Your doctor will tell you how much medicine to use. Do not use more than directed.

  • Oral routeIt is best to take this medicine with food or milk.

  • If you are using the oral powder, you can mix it with water or food (solid or liquid). Powder mixed with food should be used right away. Powder mixed in water can be stored for up to one week at room temperature or in the refrigerator.

  • Oral routeCarefully follow your doctor's instructions about any special diet.

  • Oral routeIt is best to take this medicine with food or milk.

  • If you are using the oral powder, you can mix it with water or food (solid or liquid). Powder mixed with food should be used right away. Powder mixed in water can be stored for up to one week at room temperature or in the refrigerator.

  • Your doctor will tell you how much medicine to use. Do not use more than directed.

  • Oral routeCarefully follow your doctor's instructions about any special diet.

What to do if you miss a dose of Sodium Phenylbutyrate

  • Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.

  • Ask your pharmacist, doctor, or health caregiver about the best way to dispose of any outdated medicine or medicine no longer needed.

  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

Sodium Phenylbutyrate contraindications

  • You should not use this medicine if you or your child have had an allergic reaction to sodium phenylbutyrate.

Sodium Phenylbutyrate warnings

  • Make sure your doctor knows if you are pregnant or breastfeeding, or if you have heart disease, kidney disease, liver disease, or edema (swelling from excess fluid).

  • Your doctor will do lab tests at regular visits to check on the effects of this medicine. Keep all appointments.

  • Heart rhythm problems.

  • Numbness, tingling, or burning pain in your hands, arms, legs, or feet.

  • Severe menstrual bleeding.

  • Severe vomiting or rectal bleeding.

  • Sudden or severe stomach pain, nausea, vomiting, fever, or lightheadedness.

  • Swelling in your hand, ankles, or feet.

  • Unusual bleeding, bruising, or weakness.

Sodium Phenylbutyrate interactions

  • Make sure your doctor knows if you are using probenecid (Benemid®) or steroids (such as dexamethasone, prednisolone, prednisone, Celestone®, Cortone®, Decadron®, Deltasone®, or Pediapred®). Tell your doctor if you are also using haloperidol (Haldol®) or valproic acid (Depakene®).

  • Your doctor will do lab tests at regular visits to check on the effects of this medicine. Keep all appointments.

Sodium Phenylbutyrate side effects

Serious Side Effects

  • Severe menstrual bleeding.

  • Swelling in your hand, ankles, or feet.

  • Severe vomiting or rectal bleeding.

  • Unusual bleeding, bruising, or weakness.

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing

  • Decrease in how much or how often you urinate.

  • Heart rhythm problems.

  • Numbness, tingling, or burning pain in your hands, arms, legs, or feet.

  • Sudden or severe stomach pain, nausea, vomiting, fever, or lightheadedness.

Less Serious Side Effects

  • Headache or weight gain.

  • Nausea or mild stomach pain.

  • Change in monthly periods.

  • Depression.

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