Overdose fears raised due to huge variations in cocaine purity

Analysis shows overall purity of cocaine and heroin available on the streets has increased in recent years

Unsuspecting cocaine users are placing themselves at significant risk of overdose, with research showing a massive variation in the purity of the drug sold on the streets.

And the cocaine is mixed with damaging adulterants, including a veterinary drug used to treat parasitic worm infections and painkillers that, if overused, have been linked to cancer.