Glycerol phenylbutyrate

Glycerol phenylbutyrate, sold under the brand name  Ravicti, is a medication used in the treatment of certain inborn urea cycle disorders. The medication works by preventing the harmful buildup of ammonia in the body. It is an FDA-approved prescription drug in the US. It was developed by Hyperion Therapeutics based on the existing medication sodium phenylbutyrate, and received approval in February 2013.

Economics
Hyperion has been criticized for setting a high price for the drug. The price was set at US$250,000–290,000. In 2014, the drug generated $30.8 million in net sales, far behind the older and less expensive Buphenyl ($113.6 million in sales).