While demand for such drugs has stabilised or even declined in North America, Europe and Oceania, "the problem has shifted to new markets over the past few years," the UN's Office on Drugs and Crime said in a new report.
"Asia, with its huge population and increasing affluence, is driving demand," the report said.
In its 2008 Global Assessment of amphetamine, methamphetamine (meth) and ecstasy, the UNODC found that, on an annual basis, the use of these drugs exceeded that of cocaine and heroin combined.
The global market, both wholesale and retail, for amphetamine-type stimulants or ATS was estimated at 65 billion dollars, the report said.
In 2006, almost half of Asian countries reported an increase in methamphetamine use and Saudi Arabia seized more than 12 tonnes of amphetamine, mostly in the form known as Captagon, accounting for a staggering 25 percent of all ATS seized in the world.
In South Africa, the number of seized methamphetamine laboratories had consistently gone up for the past five years while domestic consumption had increased.
Launching the report in Bangkok, UNODC's Executive Director, Antonio Maria Costa, warned that ATS "is being used as a cheap and available tonic for our fast and competitive times -- for entertainment in discos (mostly in the West), and for greater stamina in assembly lines and behind a steering wheel (in the East)."
Synthetic drugs were "falsely perceived as being harmless," Costa said. "This leads to benign neglect in attitudes, policy and enforcement that only slows down remedial action. This is dangerous."
ATS production had stabilised worldwide at about 500 tonnes per years, but while fewer labs were being seized in the US and Europe, production was rising in neighbouring countries, such as Canada, Mexico and Turkey.
Recently, the single largest seizure of ecstasy ever recorded -- 4.4 tonnes -- was made in Australia.
UNODC noted that unlike plant-based drugs such as cocaine and heroin, production of synthetic drugs was hard to trace because the ingredients were readily available for legitimate industrial purposes.
Furthermore, suppliers quickly adapt to the latest trends, and cater to local markets.
"When one lab is shut, another opens. When one type of precursor chemical is unavailable, producers switch to an alternative," Costa said.
"This presents a challenge to law enforcement since production is so close to retail outlets. Therefore, greater emphasis should be put on prevention."
Ten years ago, synthetic drugs "were a cottage industry. Now they're big business controlled by organised crime syndicates involved in all phases of the trade, from smuggling precursor chemicals, to manufacturing the drugs and trafficking," Costa said.
The countries facing the brunt of the ATS onslaught were also the least-prepared to cope, he continued.
"Some countries are in denial about the problem, and don't even report their situation to the United Nations. Others are ill-equipped to fight the pandemic, in terms of information gathering, regulatory frameworks, law enforcement, forensics, or health care," Costa said.
"The world needs to get smart about ATS before the problem is out of control," he said.
The UNODC was therefore launching a new programme, SMART, which will help governments "improve their capacity to gather, analyse and share information on ATS products, their use, and on trafficking routes."
"This should give us a better sense of how big the problem of synthetic drugs really is, and what more can be done to deal with it in terms of prevention, treatment and law enforcement," Costa said.