Methaqualone

methaqualone (brand name quaalude in the us and mandrax in the uk) is a central nervous system (cns) depressant of the quinazolinone class that acts as a sedative and hypnotic. the sedative–hypnotic activity of methaqualone was first noted by 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 with hippies and in the disco club scene.

chemistry

methaqualone, or 2-methyl-3-(2-methylphenyl)-4(3h)-quinazolinone, is a compound of the quinazolinone class. quinazolinone is a bicyclic structure containing a phenyl ring bound to another six-membered ring with two nitrogen members and a ketone group bound to r₄. in methaqualone, this structure is substituted at r₂ with a methyl group. additionally, methaqualone contains a phenyl ring with a methyl group bound to r₂ which is attached to the quinazolinone structure at r₃.

pharmacology

despite prior speculation, a 2015 study demonstrates that methaqualone exhibits distinct functional properties at the gaba receptor sites compared with other allosteric modulators, and it mediates these through a different mechanism than the barbiturates and benzodiazepines that it historically has been lumped together with.

these distinctions could contribute to the reported differences in the in vivo effects induced by methaqualone and classic cns depressants. in any case, the multifaceted functionality of methaqualone at gaba a receptors seems to be at the root of its clinical efficacy, as well as the addiction liability and recreational use associated with the drug.

it could be speculated that despite differences in targeted receptors, methaqualone essentially produces a variety of effects by binding to its receptor sites and magnifying the efficiency and effects of the neurotransmitter gamma aminobutyric acid (gaba) by acting on its receptors. as this site is the most prolific inhibitory receptor set within the brain, its modulation would explain the resulting sedating or calming effects which ensue.