Historically, orphan drugs cost more than other drugs and have received special treatment since the enactment of the U.S. Orphan Drug Act of 1983. However, these steep price increases of orphan and other specialty drugs has come under scrutiny. The average cost of a specialty drug in the US was $65,000 annually in June 2013 (about $5,416 a month). The price of Xyrem in the US has inflated by an average of 40% annually since it became available as a prescription.