Heroin is an all too powerful drug by itself. Drug dealers when dealing with new clients will usually sell pure and powerful heroin until they have a new client, a fully hooked addict. At that point, or when their stash starts to run low the pure heroin starts being cut with something else. What this something else is, is all too variable and all too dangerous.
It could just be baking soda, bringing the potency down or it could be quinine, rat poison or it could be something much stronger. There have been recent reports in the U.S. of heroin found mixed with fentanyl, or even heroin cut with carfentanil—an elephant tranquilizer! Imagine how strong a drug is, to knock out an animal the size of an elephant! Now imagine what that does to a human that consumes it.
These reports of elephant tranquiliser and fentanyl being cut in with the heroin, coincided with 35 overdoses and 2 deaths in a three day stretch in one Oklahoma town, with more overdoses nearby adding up to staggering figures. All it takes is one dealer to cut a batch with the wrong substance and you are in trouble.
Drug addicts take regular gambles with their lives, putting themselves into situations that regular people wouldn’t think of. Each time new batches of heroin are bought the Russian roulette just gets riskier. It doesn’t take more than one hit for something like fentanyl or elephant tranquilizers to cause on overdose or fatality.
Fentanyl's effects resemble those of heroin, but the same quantity will have a much more powerful effect. Carfentanil is even stronger, apparently 10,000 times stronger than morphine. These effects include euphoria, drowsiness, nausea, confusion, constipation, sedation, respiratory depression and arrest, unconsciousness, coma, and death.