Health Guide

Sodium phenylbutyrate (By mouth)

Sodium Phenylbutyrate (SOE-dee-um fen-il-BUE-ti-rate)

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

Brand Name(s):


There may be other brand names for this medicine.

When This Medicine Should Not Be Used:

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

How to Use This Medicine:

Powder, Tablet, Coated Tablet

  • Your doctor will tell you how much medicine to use. Do not use more than directed.
  • It 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.
  • Carefully follow your doctor's instructions about any special diet.

If a dose is missed:

  • 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.

How to Store and Dispose of This Medicine:

  • Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.
  • Ask your pharmacist, doctor, or health caregiver about the best way to dispose of any outdated medicine or medicine no longer needed.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.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

  • 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®).

Warnings While Using This Medicine:

  • 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.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

  • 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.
  • 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.

If you notice these less serious side effects, talk with your doctor:

  • Change in monthly periods.
  • Depression.
  • Headache or weight gain.
  • Nausea or mild stomach pain.

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Last Updated: 7/4/2018
The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites.

All rights reserved