Heroin and prescription opioids are chemically similar and can produce a similar high. Heroin is often cheaper and easier to obtain than prescription opioids, so some people switch to heroin instead. The majority of Americans using heroin (including those in treatment) reported misusing prescription opioids prior to using heroin. While prescription opioid misuse is a risk factor for starting heroin use, only a small fraction of people who misuse pain relievers switch to heroin, suggesting that prescription opioid misuse is just one factor leading to heroin use.
Fentanyl is a powerful synthetic opioid analgesic that is similar to morphine but is 50 to 100 times more potent. It’s typically used to treat patients with severe pain and patients with chronic pain who are physically tolerant to other opioids. When prescribed by a physician, fentanyl is often administered via injection, transdermal patch, or in lozenges. However, the fentanyl and fentanyl analogs associated with recent overdoses are produced in clandestine laboratories. This non-medical fentanyl is often mixed with or substituted for heroin or sold as tablets that mimic other opioids. The high potency of fentanyl greatly increases risk of overdose, especially if a person who uses drugs is unaware that a powder or pill contains fentanyl.