Opioids are a class of drug that includes the illegal drug heroin, synthetic opioids such as fentanyl, and prescription pain relievers such as oxycodone (OxyContin®), hydrocodone (Vicodin®), codeine, morphine, and many others. These drugs are chemically similar and interact with opioid receptors on nerve cells in the body and brain.
Heroin is made from morphine, a natural substance taken from the seed pod of the opium poppy plant. Heroin can be a white or brown powder, or a black sticky substance known as black tar heroin. Street names for heroin include big H, horse, and smack. People inject, snort, or smoke heroin. Some people mix heroin with cocaine, a practice called speedballing.
Fentanyl is a powerful synthetic opioid analgesic that is 50 to 100 times more potent than morphine. In its prescription form, fentanyl (Actiq®, Duragesic®, and Sublimaze®) is typically used to treat patients with severe cancer pain or to manage pain during and after surgery. However, the fentanyl that is responsible for the rapid rise in overdoses is illicitly manufactured (most often in laboratories in China) and often found mixed with or substituted for heroin, or in counterfeit prescription pills that mimic other, less potent opioids.
How are they used?
Opioid pain relievers are generally safe when taken for a short period of time and as prescribed by a doctor, but because they produce euphoria in addition to pain relief, opioids are sometimes misused. When misused, they can be taken in a different way (snorted or injected) or in a larger quantity than prescribed, or taken without a doctor’s prescription. Even regular use of opioids, when prescribed by a doctor, can lead to dependence, addiction, overdose, and even death.
Some users have switched from prescription opioids to heroin since it is often more accessible on the black market and less expensive. Because of variable purity and other chemicals and drugs mixed with heroin (such as fentanyl) on the black market, this increases risk of overdose. (SAMHSA)
When prescribed by a physician, fentanyl is often administered via injection, transdermal patch, or in lozenges. However, illicitly manufactured fentanyl is sometimes sold as a powder or on blotter paper. It is most commonly found mixed with or substituted for heroin, or in counterfeit prescription pills that mimic other, less potent opioids - such as Vicodin or Percocet. People swallow, snort, inject, or put blotter paper in their mouths so that fentanyl is absorbed through the mucous membrane. Because of its higher potency, the risk for overdose and death are higher for fentanyl compared to heroin or common prescription opioids.
Opioids act by attaching to and activating opioid receptor proteins, which are found on nerve cells in the brain, spinal cord, gastrointestinal tract, and other organs in the body. When these drugs attach to their receptors, they inhibit the transmission of pain signals. They also act on brain areas that control pleasure, inducing euphoria, particularly when they are taken at a higher-than-prescribed dose or administered in other ways than intended. Opioids can also produce drowsiness, confusion, nausea, constipation, and respiratory depression. Since these drugs also act on brain regions involved in reward, they pose a risk for addiction.
Long-Term Health Consequences
Repeated opioid use changes the function of the brain, creating long-lasting imbalances in brain circuits and hormonal systems that are not easily reversed. Studies have shown some deterioration of the brain’s white matter linked to heroin use, which may affect decision-making abilities, the ability to regulate behavior, and responses to stressful situations.
Heroin also rapidly produces tolerance and physical dependence. With physical dependence, the body adapts to the presence of the drug and withdrawal symptoms occur if use is reduced abruptly. Withdrawal may occur within a few hours after the last time the drug is taken. Symptoms include restlessness, muscle and bone pain, insomnia, diarrhea, vomiting, and cold flashes with goosebumps (“cold turkey”). Major withdrawal symptoms peak between 24–48 hours after the last dose of heroin and subside after about a week. Withdrawal is also often associated with changes in mood including depression, anxiety, fatigue, and irritability. These post-acute withdrawal symptoms can persist for many months.
Opioid Use Disorder Treatments
Effective medications approved to treat opioid use disorders include methadone, buprenorphine, and extended release naltrexone. These medications, in combination with behavioral counseling and recovery support services, help people recover from opioid use disorder.