Opioids are compounds that bind to opioid receptors. Opioids come in 4 different classes:
- Opiates, drugs derived from opium poppy (e.g., morphine and codeine);
- Semi-synthetic opioids, drugs that are synthesized from naturally occurring opiates (e.g., heroin, oxycodone, and buprenorphine);
- Synthetic opioids, drugs that are manufactured to mimic opiates (e.g., methadone, propoxyphene, and fentanyl); and
- Endogenous opioids, chemicals that are produced naturally by the body (e.g., endorphins).
Endogenous opioids bind to opioid receptors on nerve cells in the brain and other organs. This interaction is the body’s natural control response to pain. When opioid drugs enter the body (synthetic, semi-synthetic, and opiates), they can fool opioid receptors and attach to the nerve cells, mimicking natural endogenous opioids. The result of attachment causes an abnormal blocking of the perception of pain by flooding the nerve cells with dopamine. The flood of dopamine in turn can produce euphoria by affecting brain regions that mediate pleasure and rewards, but can also cause drowsiness and, occasionally, lowered respiration.
Prescribed use of opioid drugs by doctors can often produce dependence; when abused or overused, these drugs can lead to overdose and result in long-term neurological and physiological effects, such as permanent brain damage, coma, or death. The Center for Disease Control and Prevention estimates that around 78 Americans die every day form an opioid drug overdose.
According to the National Institute on Drug Abuse (NIDA), young adults (age 18 to 25) are the most frequent abusers of prescription opioids. The 2014 National Survey on Drug Use and Health reported that the average age of first use of prescription opioids was 21.2 years, and the average age of first heroin use was 28. In 2014, more than 1,700 young adults died from prescription drug overdoses.
NIDA research has shown that the incidence of heroin initiation was 19 times higher among those individuals who report prior use of prescription opioids than those with no prior use. Additionally, more than 80 percent of heroin users reported using prescription opioids prior to heroin. When opioids drugs are used in adolescence, brain development and maturation can be obstructed.
Medication-assisted treatment is the use of medications with behavioral therapy and counseling to treat substance use disorders and prevent opioid overdose. The Substance Abuse and Mental Health Services Administration indicates that early intervention through medication-assisted treatment greatly increases patient survival, increases retention in treatment, and decreases illicit opiate use. However, NIDA research has revealed that fewer than 1 million of the 2.5 million Americans that abuse opioids in 2012 received medication-assisted treatments.