Pronunciation:

SOE-dee-um fen-il-BUE-ti-rate

Brand Names:

• Buphenyl
• Olpruva
• Pheburane
• SPB11

Dosage Forms:

• Packet
• Powder
• Tablet
• Pellet

Classifications:

Therapeutic—

Endocrine-Metabolic Agent

Pharmacologic—

Histone Deacetylase Inhibitor

Uses of This Medicine:

Sodium phenylbutyrate is used together with a proper diet to help treat urea cycle disorders, including carbamylphosphate synthetase deficiency (CPS), ornithine transcarbamylase deficiency (OTC), or argininosuccinate synthetase (AS).

Ammonia is formed from the breakdown of protein in the body. If the ammonia cannot be removed by the body, then a buildup may cause serious unwanted effects. This medicine works by helping to reduce high levels of ammonia in the blood.

This medicine is available only with your doctor's prescription.

Before Using This Medicine:

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies—

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Children—

Appropriate studies performed to date have not demonstrated pediatric-specific problems that would limit the usefulness of Olpruva™ in children weighing 20 kilograms (kg) or more and with a body surface area (BSA) of 1.2 square meter (m²). Safety and efficacy have been established. Use is not recommended to treat acute hyperammonemia in children, in children weighing less than 20 kg, and in children weighing 20 kg or more with a BSA of less than 1.2 m².

Appropriate studies performed to date have not demonstrated pediatric-specific problems that would limit the usefulness of Pheburane® in children. Safety and efficacy have been established. Use is not recommended to treat acute hyperammonemia in children.

Because of Buphenyl® s toxicity, use in children weighing less than 20 kilograms (44 pounds) is not recommended.

Older adults—

Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of Pheburane® and Olpruva™ in the elderly. However, elderly patients are more likely to have age-related liver, kidney, or heart problems, which may require caution and an adjustment in the dose for patients receiving this medicine.

No information is available on the relationship of age to the effects of Buphenyl® in geriatric patients.

Breast-feeding—

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Other medicines—

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

• Probenecid

Other interactions—

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other medical problems—

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

• Diabetes or
• Edema (swelling from excess fluids in the body) or
• Fructose intolerance, history of or
• Glucose-galactose malabsorption, history of or
• Heart disease or
• Heart failure or
• Kidney disease, severe or
• Sucrase-isomaltase insufficiency, history of—Use with caution. May make these conditions worse.

• Kidney disease or
• Liver disease—Use with caution. The effects may be increased because of slower removal of the medicine from the body.

Proper Use of This Medicine:

Take this medicine exactly as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered. To do so may increase the chance of side effects. Also, do not stop using this medicine without checking first with your doctor.

This medicine comes with a patient information leaflet. Read and follow the instructions in the insert carefully. Ask your doctor if you have any questions.

For patients taking the powder form of this medicine:

• Sodium phenylbutyrate should be mixed with water or any food (solid or liquid). If the medicine is mixed with food, it should be taken right away. However, if it is mixed with water, the solution can be stored for up to one week at room temperature or in the refrigerator.
• Shake the mixed solution lightly before each use. Measure the dose with the level teaspoon or tablespoon that comes together with the package of this medicine.

Take this medicine with food.

To use the Olpruva™ oral liquid:

• Pour the entire contents of the Mix-Aid packet into 4 ounces of water in a cup and stir with spoon for 30 seconds to make the water thicker.
• Add the Olpruva™ in the mixture and stir for 15 seconds. Take the mixture within 5 minutes to prevent the coating from dissolving.
• Pour another 4 ounces of water in the cup to make sure you get full dose.
• Throw away the mixture if you have not taken it within 30 minutes of mixing.
• Do not give this medicine through a feeding tube.

To use the Pheburane® oral pellets:

• Measure the medicine with a marked measuring spoon.
• You may swallow the oral pellets with a drink (eg, water, fruit juices, protein-free infant formulas) or you may sprinkle the pellets with apple sauce or carrot puree. Take the mixture right away.
• Do not chew the pellets directly or mix with liquids.

It is important that you follow any special instructions from your doctor, such as following a low-protein diet. Also, your doctor may recommend that you take amino acid supplements. If you have any questions about this, check with your doctor.

Dosing—

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

• For the treatment of urea cycle disorders:
  • For oral dosage form (pellets):
    • Adults and children weighing 20 kilograms (kg) or more—Dose is based on body size and must be determined by your doctor. The dose is usually 9.9 to 13 grams (g) per square meter (m[2]) per day divided into 3 to 6 doses. However, the dose is usually not more than 20 g per day.
    • Children weighing less than 20 kg—Dose is based on weight and must be determined by your doctor. The dose is usually 450 to 600 milligrams per kilogram (mg/kg) of body weight per day divided into 3 to 6 doses. However, the dose is usually not more than 20 g per day.
  • For oral dosage form (powder for solution):
    • Adults, teenagers, and children weighing 20 kilograms (kg) (44 pounds) or more—The dose is based on body size and must be determined by your doctor. It is usually given 4 to 6 times a day. However, the dose is usually not more than 20 grams a day.
    • Children weighing up to 20 kg (44 pounds)—The dose is based on body weight and must be determined by your doctor. The usual dose is 450 to 600 milligrams (mg) per kilogram (kg) (205 to 273 mg per pound) of body weight per day. The dose is divided in equal amounts and given 3 to 6 times a day. However, the dose is usually not more than 20 grams a day.
  • For oral dosage form (suspension):
    • Adults and children weighing 20 kilograms (kg) or more—The dose is based on body size and must be determined by your doctor. The usual dose is 9.9 to 13 grams (g) per square meter (m[2]) per day divided into 3 to 6 doses. However, the dose is usually not more than 20 g per day.
    • Children weighing less than 20 kg—Use of the suspension is not recommended.
  • For oral dosage form (tablets):
    • Adults, teenagers, and children weighing 20 kg (44 pounds) or more—The dose is based on body size and must be determined by your doctor. It is usually given 3 times a day. However, the dose is usually not more than 20 grams (40 tablets) a day.
    • Children weighing up to 20 kg (44 pounds)—Use of the tablets is not recommended.

Missed dose—

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Pheburane® oral pellets: If you have less than 3 hours before your next scheduled dose, skip the missed dose and go back to your regular dosing schedule.

Storage—

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Throw away unused Pheburane® oral pellets 45 days after opening the bottle.

Precautions While Using This Medicine:

It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly. Blood and urine tests may be needed to check for unwanted effects.

This medicine may cause nervous system problems. Check with your doctor right away if you have confusion, headache, lightheadedness, nausea, sleepiness, tiredness, or vomiting.

In case of emergency—There may be a time when you need emergency help for a problem caused by your urea cycle disorders. You need to be prepared for these emergencies. It is a good idea to wear a Medic Alert tag at all times. Also, carry an ID card in your wallet or purse that says you have this disease and a list of all of your medicines.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Side Effects of This Medicine:

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

More common

Change in the frequency of breathing

lack of or irregular menstruation

lower back, side, or stomach pain

mood or mental changes

muscle pain or twitching

nausea or vomiting

nervousness or restlessness

swelling of the feet or lower legs

unpleasant taste

unusual tiredness or weakness

Less common

Absent, missed, or irregular menstrual periods

black, tarry stools

bleeding gums

bloating

blood in the urine or stools

bone pain

burning, tingling, numbness or pain in the hands, arms, feet, or legs

chest pain or tightness

chills

constipation

cough

darkened urine

discouragement

dizziness

fainting

fast heartbeat

feeling sad or empty

fever

headache

indigestion

irritability

joint pain, stiffness, or swelling

large, flat, blue or purplish patches in the skin

loss of appetite

loss of interest or pleasure

mood changes

muscle pain, cramps, or twitching

numbness or tingling in hands, feet, or lips

pains in stomach, side, or abdomen, possibly radiating to the back

painful or difficult urination

pinpoint red spots on the skin

rectal bleeding

seizures

sensation of pins and needles

severe or continuing stomach pain

sore throat

sores, ulcers, or white spots on the lips or in the mouth

stabbing pain

stopping of menstrual bleeding

swelling of the feet or lower legs

swollen or painful glands

trouble breathing

trouble concentrating

trouble sleeping

uneven heartbeat

unusual bleeding or bruising

yellow eyes or skin

Rare

Dryness of the mouth

fast, slow, or irregular heartbeat

increased thirst

swelling of the face

unusual weight gain

weak pulse

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less common

Body odor

burning feeling in the chest or stomach

decreased appetite

increased weight

skin rash

stomach pain or upset

Incidence not known

Change in taste

loss of taste

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

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