Pheburane is a medicine that contains the active substance sodium phenylbutyrate. It is used to treat patients who have urea-cycle disorders. These patients are not able to get rid of waste nitrogen from the body because they lack some enzymes that are usually found in the liver. In the body, waste nitrogen is in the form of ammonia, which is toxic when it accumulates, especially for the brain. Pheburane is used in patients who lack one or more of the following enzymes: carbamylphosphate synthetase, ornithine transcarbamylase, or argininosuccinate synthetase. It can be used in patients with the following forms of the disease:

• 'early-onset' disease in patients who show a complete lack of one or more of these enzymes within the first month of life;
• 'late-onset' disease in patients who show a partial lack of one or more of these enzymes after the age of one month and have had high blood ammonia levels that affected the brain’s activity.

Pheburane is a ‘hybrid medicine’. This means that it is similar to a ‘reference medicine’ containing the same active substance, but Pheburane granules are available at a lower strength and contain different excipients (inactive ingredients) to mask the unpleasant taste of the active substance. The reference medicine for Pheburane is Ammonaps.