What is the term used for the dangerous mixture of heroin and amphetamine?

The correct term for the dangerous mixture of heroin and amphetamine is speedballing. This term specifically refers to the practice of combining these two drugs, which can lead to increased effects on the user, but also significantly heightens the risk of overdose and other severe health complications.

The term "smack" is often a colloquial reference to heroin itself, and it does not describe the combination with amphetamines. "Mixing" and "blending" are more general terms that do not specifically refer to this particular combination of drugs, nor do they convey the associated dangers and cultural context of the act of speedballing. Understanding the terminology in substance use is crucial for recognizing the potential risks and consequences associated with different drug combinations.