America has been fighting the War on Drugs for decades, but the drug cartels, the suppliers and the dealers appear to be always one step ahead of the authorities.♪

（暂无翻译）

President Trump has declared the cartels, "terrorists" and labelled fentanyl, the powerful synthetic opioid, a "weapon of mass destruction".♪

（暂无翻译）

But the drug supply is changing, with other deadly synthetics being added to the mix, including strong animal tranquillisers, known on the streets as "tranq".♪

（暂无翻译）

While overdose deaths are falling, the potency of the new drugs has recovery workers worried.♪ For some the answer might lie in reducing demand, giving users support and helping them end their addiction.♪

（暂无翻译） （暂无翻译）

BBC international correspondent Quentin Sommerville and camera journalist Darren Conway travelled to Columbus, Ohio to find out more.♪

（暂无翻译）