They were barbiturate-like, apparently. Actually a anxiolytic/sedative with some hypnotic properties. Right? Someone?
It was/is prescribed as a hypnotic that was supposedly safer than short-acting barbs like Seconal and Nembutal and once barbs were nearly shut off from access to the public in the late 60's methaqualone had few competitors to contend with, especially after Doriden was pulled from US market by its manufacturer if I recall correctly. That left meprobamate and its congeners, and chloral hydrate to share the market. Benzos were then only known as weird European drugs meant for psychiatric conditions so awareness was practically inexistent. Few people realize that lack of competition was a major contributing factor to explain methaqualone's popularity in the US, while in most other countries it was just another downer among many and never gained any cult status outside the US (compare with Canada).
From personal experience (I'm not that old, was living in Canada in the 1980's when it was still commonly prescribed) I would describe the high as soft and cushy, can't really compare with anything else I have experienced as a downer. Much softer than Seconal, as in less intense of an experience but a much easier to resist urge to sleep. Closer to benzos like lorazepam but not quite... the closest I can think of is meprobamate but there again it's an approximation. As a hypnotic this drug fared very poorly because it caused all sorts of urges except sleep and duration of action was very short, 2 to 3 hours. Many doctors prescribed it off-label as an anxiolytic rather than as a hypnotic, this was/is also common in other countries even though it did not always catch on commercially.
That said methaqualone had one outstanding feature that all other downers lack: it does not cause respiratory depression on OD so some hailed it as suicide-proof. While many poorly documented claims of methaqualone causing deaths were made once the authorities entered yet another downer ban frenzy there is not a single report of this drug causing a fatality on its own, all reported fatalities involved some form of drug cocktail that often included massive amounts of alcohol and/or other potentially deadly CNS depressants such as opiates/opioids. The FDA was never able to prove methaqualone was not safer than any other downer with regards to OD related fatality incidence and that still applies to this day. Even mild benzos can kill provided enough is taken to cause respiratory failure but not methaqualone.
The above is from memory of various readings including several pieces from this site. It conflicts with Wikipedia in certain aspects but matches data from equally credible sources. There has been so much disinformation spread around about this drug that nothing should be taken at face value starting with me lol
But methaqualone's qualities were offset by a major problem. Not only was it extremely addictive but quitting was said to be second only to short-acting barbs in terms of physical turmoil. There is still a debate over the matter as some claim that this was DEA disinformation used to discredit the drug, but personally I think it's likely to be close to the truth. Physical addiction to methaqualone was very real.
