About sodium phenylbutyrate

Sodium phenylbutyrate is prescribed for people with urea cycle disorders. These are rare genetic disorders caused by a lack of an enzyme. Protein from the food you eat is usually broken down into nitrogen waste in your body. It is then converted into urea so that it can be removed from your body in your urine. Enzymes are involved in this breakdown process. If you have a lack of one of the enzymes your body needs, this means that nitrogen waste is not broken down. This leads to a build-up in your bloodstream of a nitrogen-containing substance called ammonia.

Sodium phenylbutyrate reduces the amount of ammonia in your blood by helping your body to get rid of nitrogen waste. You may also have to follow a special diet to help control your symptoms. You will be prescribed this medicine by a specialist doctor.

Before taking sodium phenylbutyrate

Some medicines are not suitable for people with certain conditions, and sometimes a medicine may only be used if extra care is taken. For these reasons, before you start taking sodium phenylbutyrate it is important that your doctor or pharmacist knows:

• If you are pregnant, trying for a baby or breast-feeding.
• If you suffer from liver, heart or kidney problems.
• If you are taking or using any other medicines. This includes any medicines you are taking which are available to buy without a prescription, such as herbal and complementary medicines.
• If you have ever had an allergic reaction to a medicine.

How to take sodium phenylbutyrate

• Before you start this treatment, read the manufacturer's printed information leaflet from inside your pack. The leaflet will give you more information about sodium phenylbutyrate and a full list of side-effects which you may experience from taking it.
• Take the tablets (or granules) exactly as your doctor has told you. The amount you need to take will depend upon your weight or size, so your doctor will tell you how much to take. Your dose will also be on the label of the pack to remind you. You must take sodium phenylbutyrate with meals. Swallow the tablets with a large glass of water to make sure they do not get lodged in your throat. If you have any difficulties swallowing the tablets, let your doctor know about this, as granules which can be mixed into water may be more suitable for you.
• If you (or your child) have been given granules to take, measure out the dose using the correct sized spoon. One flat spoonful of the small white spoon measures 1.2 g, the medium yellow spoon measures 3.1 g, and the large blue spoon measures 9.0 g. Remember to use the correct number of spoonfuls for each dose. Mix the granules with food or juice and then swallow it straightaway. The granules can be mixed with water for people being tube-fed.
• If you forget to take a dose, make sure you remember to take one with your next meal and then continue as usual. Leave at least three hours between doses, and never take two doses together to make up for a forgotten dose.

Getting the most from your treatment

• You should follow the dietary advice that your doctor or dietician has given you. It is important that you eat a special diet which is low in protein alongside this medicine.
• Try to keep your regular appointments with your doctor. This is so your doctor can check on your progress. Your doctor will want to do blood tests to check on the levels of ammonia in your blood.
• Treatment with sodium phenylbutyrate is usually long-term. Continue to take it unless you are told otherwise by your doctor.
• If you buy any medicines, check with a pharmacist that they are safe to take with sodium phenylbutyrate. Also, if you are having any medical treatment, tell the person carrying out the treatment that you are taking this medicine.

Can sodium phenylbutyrate cause problems?

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. These usually improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following side-effects continue or become troublesome.

If any of these become troublesome, speak with your doctor for advice

Your doctor will have discussed with you the possibility of other unwanted side-effects such as blood disorders. If you experience any symptoms which you think may be due to this medicine, speak with your doctor as soon as possible.

How to store sodium phenylbutyrate

• Keep all medicines out of the reach and sight of children.
• Store in a cool, dry place, away from direct heat and light.

Important information about all medicines