Generic Name: sodium phenylbutyrate (SOE dee um FEN il BUE ti rate)Brand Names: Buphenyl
Sodium phenylbutyrate is converted to a substance in the body that helps the kidneys eliminate waste substances from the body. These waste substances can produce ammonia, which is toxic if it builds up in your blood.
Sodium phenylbutyrate is used to treat urea cycle disorders in people who lack certain liver enzymes needed to properly eliminate waste substances from the body. This medication helps prevent a build-up of ammonia in the blood.
Sodium phenylbutyrate may also be used for other purposes not listed in this medication guide.What is the most important information I should know about sodium phenylbutyrate?Even with treatment, urea cycle disorders can cause a build-up of ammonia in the blood which can result in life-threatening side effects. Seek emergency medical attention if you notice any signs of ammonia build-up, including mood or behavior changes, memory loss, thinking problems, muscle twitching, back and forth movement of the eyes, vomiting, increasing weakness, slurred speech, seizure (convulsions), and fainting.
Before taking sodium phenylbutyrate, tell your doctor if you have congestive heart failure, high blood pressure, severe kidney disease, swelling or fluid retention, or a seizure disorder.Take this medication with each meal. Divide your total daily dose among all of your meals for the day.
Sodium phenylbutyrate is only part of a complete program of treatment that may also include diet, dialysis, or other medications. Follow your diet and medication routines very closely.Do not give this medication to a child who weighs less than 44 pounds unless your doctor tells you to.What should I discuss with my health care provider before taking sodium phenylbutyrate?
Before using sodium phenylbutyrate, tell your doctor if you are allergic to any drugs, or if you have:
congestive heart failure;
high blood pressure;
severe kidney disease;
swelling or fluid retention; or
epilepsy or other seizure disorder.
If you have any of these conditions, you may not be able to take sodium phenylbutyrate, or you may need a dose adjustment or special tests to safely take this medication.
Your doctor will tell you if any of your medication doses need to be changed.FDA pregnancy category C. It is not known whether sodium phenylbutyrate is harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment. It is not known whether sodium phenylbutyrate passes into breast milk or if it could harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby. Do not give this medication to a child who weighs less than 44 pounds unless your doctor tells you to.
Take this medication exactly as prescribed by your doctor. Do not take it in larger amounts or for longer than recommended. Follow the directions on your prescription label.Take this medication with each meal. Divide your total daily dose among all of your meals for the day.
Sodium phenylbutyrate powder should be mixed with food before consuming.Shake the powder lightly before mixing it with food. Do not stop using this medication without your doctor's advice, even if you feel better. If the urea cycle disorder is not under control, you may have a build-up of ammonia, which can cause life-threatening side effects.
Call your doctor right away if you have any signs of infection such as fever, chills, redness, swelling, body aches, or weakness. An infection may cause your condition to go out of control even while you are taking sodium phenylbutyrate.
You may need to take sodium phenylbutyrate for the rest of your life. It is important to use the medication regularly to get the most benefit. Get your prescription refilled before you run out of medicine completely.
Sodium phenylbutyrate is only part of a complete program of treatment that may also include diet, dialysis, or other medications. Follow your diet and medication routines very closely.Store sodium phenylbutyrate at room temperature away from moisture and heat.
See also: Sodium phenylbutyrate dosage in more detail
Take the missed dose as soon as you remember. If it is almost time for your next dose, wait until then to take the medicine and skip the missed dose. Do not take extra medicine to make up the missed dose.Be sure to take the medication with food.
Symptoms of a sodium phenylbutyrate overdose are not known.
Follow your doctor's instructions about any restrictions on food, beverages, or activity while you are using sodium phenylbutyrate.
fast, slow, or uneven heart rate;
swelling, rapid weight gain;
feeling like you might pass out; or
changes in mood, personality, or behavior.
Less serious side effects may include:
changes in menstrual periods;
loss of appetite;
increased body odor;
unusual or unpleasant taste in your mouth.
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.
Usual Adult Dose for Urea Cycle Disorders:
The usual total daily dose for patients with urea cycle disorders is 9.9 to 13 g/m2/day in larger patients. The tablets and powder are to be taken in equally divided amounts with each meal or feeding (i.e., three to six times per day).Sodium phenylbutyrate must be combined with dietary protein restriction and, in some cases, essential amino acid supplementation.
Usual Pediatric Dose for Urea Cycle Disorders:
The usual total daily dose for patients with urea cycle disorders is 450-600 mg/kg/day in patients weighing less than 20 kg, or 9.9-13 g/m2/day in larger patients. The tablets and powder are to be taken in equally divided amounts with each meal or feeding (i.e., three to six times per day). The tablets are for children weighing more than 20 kgSodium phenylbutyrate must be combined with dietary protein restriction and, in some cases, essential amino acid supplementation.
The following drugs can interact with sodium phenylbutyrate. Tell your doctor if you are using any of these:
valproic acid (Depakene);
probenecid (Benemid); or
steroids such as prednisone, fluticasone (Advair), mometasone (Asmanex, Nasonex), dexamethasone (Decadron, Hexadrol) and others.
This list is not complete and there may be other drugs that can interact with sodium phenylbutyrate. Tell your doctor about all your prescription and over-the-counter medications, vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start a new medication without telling your doctor.