I have in the past discussed the fact that a substantial amount of recreational drug being sold as "Ecstasy" on the street contains psychoactive constituents other than 3,4-methylenedioxymethamphetamine (MDMA). This is old news and you can play around with one source of data for yourself at ecstasydata.org*. In addition, I have mentioned the UK explosion in use of 4-methylmethcathinone (4-MMC, aka mephedrone) over the past year (here, here, here, here).
Brunt and colleagues have provided an update from the Netherlands Drug Information and Monitoring System which obtains drug samples, described in their prior paper, from recreational users at clubs and somehow turned over to police. For this paper they have included analysis from 12,331 tablets collected from 2008-2009. The first major observation is that the proportion of tablets containing zero MDMA increased sharply in late 2008 which is a big change from the ~90% MDMA-containing samples in prior years. Something on the order of 50-60% of the Ecstasy obtained in the Netherlands in 2009 didn't have any MDMA in it. Bummer, dude.
The other fascinating thing is that even though the usual suspect non-MDMA components were found (23-54% mCPP, methamphetamine/amphetamine, caffeine are common) the substituted cathinone 4-MMC/mephedrone is a new player.
A total of 995 (11.5% of the total ) tablets sourced from the DIMS system in 2009 contained only mephedrone. The authors note that this compound was also found in samples derived from over 100 police seizures. Although it is unclear how the proportions match up, at least the sample biases represented from the voluntary (?) user submissions and the police actions are grossly comparable in the sense that mephedrone tablets are appearing in the Dutch market. The paper goes on to note that 4-MMC is not yet "under the Scheduled Substances Act" so presumably it is a situation much like the UK up until April of 2010.
A final note of interest is the downturn in the proportion of non-MDMA tablets in late 2009- it will be interesting to see if this MDMA-drought was a shortlived blip or if actions such as Cambodia, Vietnam and Thailand finally getting serious about controlling the production of the safrole oil used as a precursor in MDMA manufacture is having a lasting effect on world markets.
One thing that I would personally like a little more clarity on is the degree to which the authors assert that the tablets they are analyzing were "sold as ecstasy". Given the popularity of the drug under its own name in the UK, one wonders if it is merely being marketed as mephedrone/4-MMC instead of deceptively as "Ecstasy" which I think is commonly understood to mean MDMA. There is also the usual problem with samples sourced from users in this paper- there could always be a substantial bias to submit or turn over tablets (which are likely batch-identifiable by stampings/color) of unexpected or suspicious subjective character. Likewise, it is hard to determine marketshare for a particular batch or appearance of tablet. This makes it hard to infer what the constituents are in the population of pills actually being consumed by users with high accuracy. Nevertheless these data are very welcome since across time and geographical region we can get some confidence on relative MDMA content, the appearance of new drugs, etc.
*Since I mentioned the pill testing outfit ecstasydata.org at the top, I should note that a search for mephedrone pulls up 5 different tablets, all sourced from Zurich (it is possible that the other source laboratories are not testing for 4-MMC yet). All 5 contain caffeine and two contain MDMA in addition to the 4-MMC.
Brunt TM, Poortman A, Niesink RJ, & van den Brink W (2010). Instability of the ecstasy market and a new kid on the block: mephedrone. Journal of psychopharmacology (Oxford, England) PMID: 20826554