Cause for alarm, as flesh-eating zombie drug sweeping US linked to 11 deaths in Britain telegraph.co.uk - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from telegraph.co.uk Daily Mail and Mail on Sunday newspapers.
Xylazine, or tranq , has been found in hard opioids like heroin or fentanyl but also worryingly in cocaine, counterfeit codeine and Valium tablets, and even in some cannabis vapes.