Simon Cotton takes a look at those compounds that find themselves in the news or relate to our everyday lives
Are we talking about cats?
No. Meow meow is the latest 'party' drug, which has been linked to over 20 deaths in England and Scotland. Made in China and available as a white powder or tablets, its chemical name is mephedrone (1)- ie methylmethcathinone. Don't confuse it with methadone, the drug used to treat opioid dependence, or with methedrine, another name for methamphetamine.
So it's an illegal substance?
It is illegal to possess or sell mephedrone in much of Scandinavia, Israel and the US. As a result of the fatalities, the same is now true in the Channel Islands and it is likely to be banned in the UK soon.
Why do people take it?
It is said to have similar effects to Ecstasy (and is cheaper) - it is a mood-enhancer and a stimulant.
Why is that?
Possibly because it has a similar structure to both Ecstasy (2) and methamphetamine (3).
Are there any other drugs like it?
The structure of mephedrone is related to that of cathinone (4), the main active constituent of khat, obtained from an evergreen shrub (Catha edulis) that grows in East Africa. Along with coffee, khat is the main cash crop in the Yemen. It also forms an important part of social life of most Yemenis, who chew the leaves and young shoots to get 'highs'.
What is cathinone?
S-Cathinone (4) is a stimulant, which produces similar symptoms to S-methamphetamine (3) and S-amphetamine (5). The three molecules have the same absolute (three dimensional) configuration, so that they can fit chiral protein receptors and presumably elicit similar responses. After the leaves are picked, cathinone is oxidised quite quickly. Because of this, only fresh leaves are pharmacologically active and buyers make a point of purchasing them fresh.
What's the problem with khat?
It can produce symptoms similar to amphetamine - people become alert, cannot sleep, and can have heart palpitations. It is also an appetite suppressant and causes severe constipation. Repeated chewing may lead to mouth cancer. There have also been reports of what appears to be khat-related psychosis.
What about Mephedrone?
It's not been around long enough to know its long-term effects, though several deaths have been linked to it and that one long-term user was admitted to a psychiatric unit. Another user is said to have ripped off part of his skin after experiencing the feeling of insects crawling over his body - a common side effect of methamphetamine abuse.