Global seizures of these kinds of drugs more than doubled between 2010 and 2012, according to the latest available data cited in the UNODC's annual report.
While the global number of drug users remained stable, the Vienna-based agency pointed out that an estimated 34.4 million people took amphetamines in 2012, a figure that was topped only by cannabis users.
More recent data have been available for opium production acreage, which jumped 36 per cent last year in Afghanistan, the world's largest supplier.
Meanwhile, cocaine supply from South American countries has decreased. However, consumption is increasing on that continent, UNODC said.
DPA