Ravicti (glycerol phenylbutyrate) binds with other substances in the liver and kidneys to help eliminate nitrogen from the body. Excess nitrogen can cause hyperammonemia (HYE-per-AM-moe-NEE-mee-a), a build-up of ammonia in the blood. Ammonia is very toxic when it circulates in blood and tissues and can cause permanent brain damage, coma, or death.
Ravicti helps prevent a build-up of ammonia in the blood in people with urea cycle disorder. This medicine is used in adults and children who are at least 2 years old. Ravicti will not treat hyperammonemia.
Ravicti is usually given together with a low-protein diet and sometimes dietary supplements.
Ravicti may also be used for purposes not listed in this medication guide.
Important information
Ravicti should not be given to a child under 2 months old.
Before taking this medicine
You should not use Ravicti if you are allergic to glycerol phenylbutyrate.
Ravicti should not be given to a child under 2 months old. Do not give this medicine to a child younger than 2 years old without medical advice.
To make sure Ravicti is safe for you, tell your doctor if you have:
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liver or kidney disease;
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pancreas disorder;
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stomach or intestinal disorder,
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a condition called NAGS (N-acetylglutamate synthase) deficiency; or
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if you take haloperidol or probenecid, or if you use a steroid medicine (beclomethasone, dexamethasone, fluticasone, prednisone, and others).
FDA pregnancy category C. It is not known whether Ravicti will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medicine.
See also: Pregnancy and breastfeeding warnings (in more detail)
It is not known whether glycerol phenylbutyrate passes into breast milk or if it could harm a nursing baby. You should not breast-feed while using this medicine.
How should I take Ravicti?
Use Ravicti exactly as prescribed by your doctor. Follow all directions on your prescription label. Your doctor may occasionally change your dose to make sure you get the best results. Do not take this medicine in larger or smaller amounts or for longer than recommended.
Ravicti is usually taken 3 times per day. Take with food.
Measure liquid medicine with the dosing syringe provided, or with a special dose-measuring spoon or medicine cup. If you do not have a dose-measuring device, ask your pharmacist for one.
Ravicti can also be given through a nasogastric (NG) or gastric feeding tube as follows: After measuring the correct dose in the syringe, attach it to the feeding tube and push the plunger down to empty the syringe into the tube. Then flush the tube with 2 tablespoons of water and allow it to drain. Follow this with 2 more tablespoons of water to wash the contents down.
If you switch from sodium phenylbutyrate to glycerol phenylbutyrate, your dose will not be the same. Follow your doctor"s dosing instructions very carefully.
Ravicti is only part of a complete program of treatment that may also include a special diet and other medications. It is very important to follow the diet plan created for you by your doctor or nutrition counselor. You should become very familiar with the list of foods you should eat or avoid to help control your condition.
To be sure Ravicti is helping your condition and is not causing harmful effects, your blood will need to be tested often. A buildup of ammonia in the blood can quickly cause brain injury or death. Do not miss any follow up visits to your doctor for blood tests. Every person with a urea cycle disorder should remain under the care of a doctor.
Your name may be listed on a Urea Cycle Disorder registry. This is to collect information about people with these disorders and to evaluate the effects of treatment.
Store at room temperature away from moisture and heat.
Ravicti dosing information
Usual Adult Dose of Ravicti for Urea Cycle Disorders:
Initial dose:
-In Phenylbutyrate-Naive Patients: 4.5 to 11.2 mL/m2/day (5 to 12.4 g/m2/day) given in 3 equally divided dosages (round up to the nearest 0.5 mL) with food. In patients with some residual enzyme activity not adequately controlled with dietary restriction the recommended starting dose is 4.5 mL/m2/day.
-In Patients switching from Sodium Phenylbutyrate: daily dosage of glycerol phenylbutyrate in mL equals the daily dosage of sodium phenylbutyrate (g) x 0.86
Maximum dose: 17.5 mL
Comments:
-To determine the starting dose, consider the patient"s residual urea synthetic capacity, dietary protein requirements, and diet adherence. An initial estimated glycerol phenylbutyrate dose for a 24 hour period is 0.6 mL glycerol phenylbutyrate per gram of dietary protein ingested per 24 hour period.
-Must use with dietary protein restriction and sometimes with dietary supplements
-Not indicated for the treatment of acute hyperammonemia in patients with UCDs
-Safety and efficacy for treatment of N-acetylglutamate synthase (NAGS) deficiency has not been established.
Usual Geriatric Dose of Ravicti for Urea Cycle Disorders:
Comments: Start at the low end of the dosing range to account for decreased hepatic, renal, or cardiac function and concomitant disease or other drug therapies.
Usual Pediatric Dose for Urea Cycle Disorders:
Initial dose:
-In Phenylbutyrate-Naive Patients: 4.5 to 11.2 mL/m2/day (5 to 12.4 g/m2/day) given in 3 equally divided dosages (round up to the nearest 0.5 mL) with food. In patients with some residual enzyme activity not adequately controlled with dietary restriction the recommended starting dose is 4.5 mL/m2/day.
-In Patients switching from Sodium Phenylbutyrate: daily dosage of glycerol phenylbutyrate in mL equals the daily dosage of sodium phenylbutyrate (g) x 0.86
Maximum dose: 17.5 mL
Comments:
-To determine the starting dose, consider the patient"s residual urea synthetic capacity, dietary protein requirements, and diet adherence. An initial estimated glycerol phenylbutyrate dose for a 24 hour period is 0.6 mL glycerol phenylbutyrate per gram of dietary protein ingested per 24 hour period.
-Must use with dietary protein restriction and sometimes with dietary supplements
-Not indicated for the treatment of acute hyperammonemia in patients with UCDs
-Safety and efficacy for treatment of N-acetylglutamate synthase (NAGS) deficiency has not been established.
What happens if I miss a dose?
Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.
What happens if I overdose?
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.
What should I avoid while taking Ravicti?
Follow your doctor"s instructions about any restrictions on food, beverages, or activity.
Ravicti side effects
Get emergency medical help if you have any of these signs of an allergic reaction to Ravicti: hives; cough, wheezing, difficult breathing; feeling like you might pass out; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have any signs of hyperammonemia:
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weakness, lack of energy;
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thinking problems, changes in behavior, feeling irritable;
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breathing problems;
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feeding problems; or
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seizure (convulsions).
Also call your doctor at once if you have:
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drowsiness, unusual tiredness;
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a light-headed feeling, like you might pass out;
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confusion, ongoing headache, vomiting;
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altered sense of taste; or
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hearing problems.
Common Ravicti side effects may include:
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nausea, vomiting, stomach pain;
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gas, diarrhea;
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loss of appetite;
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dizziness, tired feeling; or
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occasional headache.
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.
See also: Side effects (in more detail)
What other drugs will affect Ravicti?
Tell your doctor about all medicines you use, and those you start or stop using during your treatment with Ravicti, especially:
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divalproex sodium; or
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valproic acid.
Other drugs may interact with glycerol phenylbutyrate, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.
