Methaqualone, brand name Quaalude (sometimes styled Quāālude) /ˈkweɪluːd/ in the US and Mandrax in the UK, is a sedative-hypnotic drug of the quinazolinone class that acts as a general central nervous system depressant.The sedative–hypnotic activity of methaqualone was first noted by Indian researchers in the 1950s and in 1962 methaqualone itself was patented in the US by Wallace and Tiernan. Its use peaked in the early 1970s as a hypnotic, for the treatment of insomnia, and as a sedative and muscle relaxant. It is still produced and used clandestinely as a recreational drug throughout the world. The drug was popular in the 1970s disco club scene.