Heroin users in my community in Massachusetts came to realize that fentanyl had entered the drug supply when overdose numbers exploded. Physicians like me have seen a rise in unintentional fentanyl use from people buying prescription opioids and other drugs laced, or adulterated, with fentanyl. From Xanax to cocaine, drugs or counterfeit pills purchased in nonmedical settings may contain life-threatening amounts of fentanyl. Buying drugs on the street is a game of Russian roulette.
