This medication is used along with diet changes for long-term treatment of a certain inherited disorder (urea cycle disorder). It helps remove a certain chemical (ammonia) from the body. Too much ammonia in the body can cause brain damage and sometimes death.

This medication should not be used to treat sudden, severely high levels of ammonia in the body. Get medical help right away if you have sudden symptoms of too much ammonia, such as trouble thinking, vomiting, irritability, trouble speaking, trouble walking, fainting.

Read the Medication Guide provided by your pharmacist before you start taking glycerol phenylbutyrate and each time you get a refill. Learn all preparation and usage instructions. If you have any questions, ask your doctor or pharmacist.

Take this medication by mouth exactly as directed by your doctor. The dosage is based on your body size, medical condition, and response to treatment. The total daily dose should be divided into equal amounts and taken with each meal or feeding (such as 3 to 6 times daily). Do not increase or decrease your dose without your doctor's approval.

Carefully measure the dose using an oral syringe. Do not use a household spoon because you may not get the correct dose.

If you are giving this medication through a tube into the stomach (nasogastric or gastric tube), ask your health care professional for detailed instructions on how to properly give it.

Use this medication regularly to get the most benefit from it. To help you remember, take it at the same times each day.

Loss of appetite, diarrhea, or gas may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including:

• nausea
• vomiting
• headache
• drowsiness/lightheadedness
• mental/mood changes (such as confusion)
• tiredness
• decreased hearing

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before taking this medication, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

• disease of the pancreas
• difficulty absorbing fat from food (malabsorption)
• kidney disease
• liver disease

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

It is unknown if this medication passes into breast milk. Consult your doctor before breastfeeding.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669.

Do not share this medication with others.

Lab and/or medical tests (such as ammonia/amino acid levels, urine tests, drug levels) should be done while you are taking this medication. Keep all medical and lab appointments. Consult your doctor for more details.

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up. It is very important to take the full amount prescribed for each 24-hour period.

Store at room temperature away from light and moisture. Do not store in the bathroom. Different brands of this medication may have different storage needs. Check the product package for instructions on how to store your brand, or ask your pharmacist. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.