Syria has become a major amphetamines exporter and consumer as the trauma of the country's brutal civil war fuels demand and the breakdown in order creates opportunity for producers.

Drugs experts, traders and local activists say Syrian production of the most popular of the stimulants, known by its former brand name Captagon, accelerated in 2013, outpacing production in other countries in the region such as Lebanon.

The drug was first produced in the West in the 1960s to treat hyperactivity, narcolepsy and depression, but by the 1980s was banned in most countries because of its addictive properties and no longer has a legitimate medical use. Its active ingredient, fenethylline, is metabolized by the body into the stimulants amphetamine and theophylline.

Syrian state media regularly mention Captagon pills as one of the items government forces seize alongside weapons when they capture rebel fighters or raid their bases.

A drug control officer in the central city of Homs told Reuters he had observed the effects of Captagon on protesters and fighters held for questioning.

"We would beat them, and they wouldn't feel the pain. Many of them would laugh while we were dealing them heavy blows," he said. "We would leave the prisoners for about 48 hours without questioning them while the effects of Captagon wore off, and then interrogation would become easier."