"when we think about the deaths themselves, most of the people are dying in large part because they combine opioids with another sedative, like alcohol, like a benzodiazepine. A benzodiazepine is something like Xanax. They also combine opioids with older antihistamines. Those sorts of things, they increase the risk associated with opioids...Much of the heroin on the street today is now being tainted with this drug called fentanyl. Fentanyl is about 50 to a hundred times more potent than heroin, just simply means that less of the drug is needed to produce the required effect. But unsuspecting users may take the amount that they usually take with heroin, thinking that it’s heroin, when in fact it’s fentanyl."