Sodium phenylbutyrate is used together with personalised dietary programmes to help treat individuals with urea cycle disorders (inherited group of diseases caused by a deficiency of certain liver enzymes resulting in increased ammonia levels in the blood).
This medicine helps to eliminate nitrogen waste, thereby reducing the amount of ammonia in your body.
Take Sodium phenylbutyrate exactly as directed by your doctor or according to the instructions on the label. Do not take more or less than instructed by your doctor.
Take it together with food or immediately after a meal. Try to take it at the same time each day.
Sodium phenylbutyrate is available as a tablet, powder, or granules.
If you are taking the tablet, swallow it whole with a glass of water.
If you are taking the powder, use the dosing spoon provided with each bottle to measure out your dose. Refer to the package insert for directions on how to use the dosing spoon. You may dissolve the powder in water or mix it with solid or liquid foods. Take the mixture immediately. If not needed immediately, the powder dissolved in water may be stored for up to 1 week at room temperature or in the refrigerator.
If you are taking the granules, use the calibrated spoon supplied with each bottle to measure out your dose. Refer to the package insert for directions on how the calibrated spoon should be used. The granules may be directly taken with a drink (e.g. water, fruit juices, protein-free infant formula) or sprinkled on a spoonful of solid foods (e.g. apple sauce, mashed potatoes). Take the mixture immediately.
If you are on nasogastric or gastrostomy feeding, you may use the powder mixture. If you are planning to use the granules, check with your doctor or pharmacist first as certain brands of Sodium phenylbutyrate granules may or may not be given by tube feeding. Always flush the tubing with water after each dose of this medicine to ensure that the full dose is taken.
It may be necessary for you to take this medicine for a long time, such as for a few years. Your doctor will advise you on the treatment timeframe.
Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and return to your normal dosing schedule.
DO NOT double a dose under any circumstances.
If you often forget to take your medicine, let your doctor and pharmacist know.
Sodium phenylbutyrate is not indicated for the management of sudden excessive ammonia levels in the blood. Alert your doctor immediately if you experience vomiting, confusion, fits or seizures, or loss of consciousness while being treated with this medicine.
Do not take Sodium phenylbutyrate if you are pregnant or planning to have a baby soon. If you become pregnant while being treated with this medicine, alert your doctor immediately. Sodium phenylbutyrate may cause harm to your unborn child. You must use proven birth control methods while taking this medicine.
Do not take this medicine if you are breastfeeding.
Inform your doctor if you have the following conditions:
- heart disease
- inborn errors of metabolism (rare inherited disorder in where the body cannot breakdown certain nutrients)
- low sodium or sodium-free diet
- diabetes
- kidney disease
- liver disease
Be sure to check with your doctor or pharmacist before giving this medicine to a child. Children may be more sensitive to the side effects.
Why is it important to keep my appointments with the doctor?
Keep your appointments with your doctor. Your doctor needs to monitor your condition and check your response to the medication regularly.
- Routine tests (e.g. complete blood count, liver and kidney function, ammonia, amino acid and electrolyte levels) may be done while you are being treated with Sodium phenylbutyrate. Your doctor will advise you about how often you need to have these tests.
- Regular monitoring for signs and symptoms of excessive ammonia levels in the body may also be needed.
Sodium phenylbutyrate may cause any of the following side effects: headache, nausea, vomiting, constipation, stomach pain, taste disturbance, decreased appetite, irritability, depression, irregular or absence of menstruation, skin rash, and abnormal skin odour.
Some side effects may need immediate medical help. Alert your doctor quickly if you experience any of the following:
- swelling of ankles, hands or feet, weight gain, indentations in the skin after the swollen area is pressed
- vomiting, unsteadiness in walking, confusion, loss of consciousness, fits or seizures
- drowsiness, light-headedness, tiredness, partial loss of hearing, disorientation, impaired memory
Inform your doctor if any of these side effects do not go away or are severe, or if you experience other side effects.
Inform your doctor and pharmacist if you are taking any of these medicines:
- probenecid (medicine for gout, an abnormal metabolism of uric acid)
- valproic acid (medicine for fits or seizures)
- haloperidol (medicine for mood disorders)
- anti-inflammatory medicines e.g. prednisone, cortisone
This list does not include all medicines that may interact with Sodium phenylbutyrate.
Always notify your doctor and pharmacist if you are taking any other medicines, including herbal tonics such as traditional Chinese medicines, supplements and medicines that you buy without a prescription.
Avoid alcohol.
It is important to adhere to the diet prescribed by your doctor or dietitian.
Store in a cool, dry place away from the reach of children.
Medicines must not be used past the expiry date.
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