What Are Opioids?

It seems as though every time we turn on the news, there are more reports of opioid overdoses resulting in deaths. The United States is experiencing an epidemic of opioid abuse and addiction that is affecting people of all backgrounds and ages. To make sense of the conversations happening around opioids, we break down what they are, how they are used legally and illegally, and what happens when abuse turns into addiction.

Opioids vs. Opiates: What’s the Difference?

Though the terms are often used interchangeably, there are some technical distinctions between the concepts of opiates and opioids.

The term opiates, as a group of substances, is often reserved for the handful of substances that are contained in the opium poppy, such as codeine, morphine, and thebaine. Pharmaceutical formulations of codeine and morphine are widely utilized painkillers in clinical situations.

The term opioids, on the other hand, commonly refers to semi-synthetic or fully synthetic substances that, like their opiate counterparts, are active at opioid receptors throughout our bodies. In some case, these substances are manufactured with just a few chemical modifications between the final product and an opioid precursor; heroin, for example, is chemically very similar to morphine.

That is because opiates are a class of drug derived from the opium poppy plant, while opioids are synthetic and semisynthetic derivations.

You’ll notice that this list of naturally occurring opiates includes both legal and illegal drugs, and there are still more prescription painkillers that fit the bill:1

Opiate derivatives include: 1

Full synthetic, or man-man, opioids include: 1

For simplicity’s sake, we will refer to both opiates and opioids as opioids for the rest of this article.

What Opioids Do

In most cases, the goal of prescription opioid therapy is pain relief. Opioid agonist drugs bind to and activate various opioid receptors throughout the body. Depending on the specific set of target receptors, this activation can result in several physiological changes, including altered pain perception and a rewarding euphoric sensation. These drugs act on opioid receptors in the brain, filling them and therefore blocking pain and increasing pleasure.

In short, opioid drugs not only decrease symptoms in those who suffer from moderately severe pain, but they also have certain dose-dependent, mind-altering effects. Especially when used in excess of a prescribed dosing regimen, opiates can elicit a euphoric and sought-after “high.”

Because of their reinforcing properties, these drugs are also highly addictive; even consistent prescription use can lead to the development of significant tolerance and physical dependence, which may lay the groundwork for eventual escalating, compulsive misuse and, ultimately, addiction.

Opioids are some of the most abused drugs in the world. The United Nations Office on Drugs and Crime estimates that the global number of opioid users is around 53 million, up drastically from previous estimates. Opioids were involved in two-thirds of all drug-use deaths in 2017.2

Opioid Abuse Concerns

At the time of the National Survey on Drug Use and Health (NSDUH) in 2016, an estimated 11.8 million Americans (aged 12 and older) abused opioids in the past year; 948,000 of these people were abusing heroin. Opioid drug abuse is not confined to one demographic; however, the largest percentage of people misusing these drugs in 2016 were 26 or older.3

Any use of heroin or nonmedical use of a prescription opioid is considered abuse. Prescription opioids may be abused taking more pills or tablets than prescribed, by chewing them, or by crushing them to smoke, inject, or snort the resulting powder. Heroin is commonly encountered as a whitish or brown powder that may be smoked, snorted, or injected.

In October 2014, many prescription opiates were rescheduled from Schedule III to the more tightly controlled Schedule II by the Drug Enforcement Administration (DEA), the American Society of Addiction Medicine (ASAM) reports.4

As a result of new formulations of these medications and stricter regulations, abuse rates of prescription pain relievers dropped initially; however, heroin abuse rates began to creep up.5 Heroin offers a cheap, and often more accessible, alternative to harder-to-get prescription opiates.

Heroin abuse rates for those between the ages of 18 and 25 more than doubled between 2002 and 2012, and abuse increased in virtually all age, socioeconomic, gender, and cultural demographics, the Centers for Disease Control and Prevention (CDC) reports.6

Dangers of Opioid Abuse

pill bottle of opioids next to syringes with heroinOpioids slow respiration, can cause nausea and vomiting, and impair decision-making abilities and mental functioning as well as motor coordination and reflexes.7

Long-term side effects of heroin, specifically, may depend on how a person consumes it. Those who snort heroin risk damage to their nasal septum and mucosal tissue in their nose. Long-term side effects of injection-based heroin abuse, as highlighted by NIDA, include:8

  • Infections of heart valves and lining.
  • Rheumatologic issues, including arthritis.
  • Collapsed veins.
  • Bacterial infections.
  • Kidney and liver disease.
  • Abscesses and soft tissue infections.
  • Contraction of HIV/AIDS and/or hepatitis B and C.

More general long-term side effects of heroin abuse include:8

  • Respiratory issues and potential lung infections or disease like tuberculosis or pneumonia.
  • Irregular menstrual cycles in women.
  • Sexual dysfunction in men.
  • Increased depression.
  • Worsening symptoms of co-occurring mental health or medical conditions.

Immediate consequences of any opioid or opiate abuse include the risk of a potentially fatal overdose. Long-term use of an opiate drug can lead to drug dependence and addiction.9

Impact of Opioid Drug Dependence from Chronic Use

Opioid drugs are considered to be some of the most addictive psychoactive substances out there. The makers of the prescription drug OxyContin, Purdue Pharma, even warn people that using this drug under the direction of a medical provider, and with a medically necessary prescription, can still be habit-forming and lead to addiction.10

Tolerance can set in quickly with chronic opioid use. An individual will then need to take higher doses of the opiate more often in order to keep feeling the drug’s effects. Increasing the dosage and frequency of use may more quickly lead to the development of physical dependence.

After physical drug dependence develops, opioid users are at risk of experiencing withdrawal symptoms when the drug wears off; acute heroin withdrawal symptoms may begin within 12 hours of last use. Acute opioid withdrawal symptoms can be quite uncomfortable and difficult to endure. They include:11

  • Anxiety.
  • Agitation.
  • Insomnia.
  • Dilated pupils.
  • Nausea and vomiting.
  • Abdominal cramps.
  • Diarrhea.
  • Muscle aches.
  • Sweating.
  • Goosebumps.
  • Runny nose.
  • Increased production of tears.

Since the side effects of opioid withdrawal can be significant, treating professionals often utilize medical detox and treatment to manage.11 Medications, such as methadone or buprenorphine, can be used during medical detox to ease the body’s transition off opioids, helping to decrease withdrawal symptoms and reduce cravings.12 Beyond the withdrawal period, these medications may also be used as part of a larger comprehensive treatment program that includes intensive therapy.

Opioid Overdose Epidemic

An opioid overdose can be a medical emergency.

An overdose on an opioid typically becomes fatal when respiration rates are lowered too much. An individual may struggle to breathe and then stop breathing altogether.13

Body temperature also drops significantly, and lips, skin, and nails may turn blue and be cold and clammy to the touch. Pulse is weak and heart rate becomes irregular during an opiate overdose. A person likely becomes confused and drowsy and may lose consciousness during an overdose. Pupils may become markedly constricted.13

An opioid overdose may be reversed by the prompt administration of an opioid antagonist, such as Narcan (naloxone).14 Many first responders carry this medication, and, in the face of the opioid epidemic, it is becoming increasingly accessible in community pharmacies across the country.15

The CDC warns that individuals abusing heroin also abuse other drugs around 90 percent of the time. It is also widely observed that patients may co-use other drugs with opioids to achieve heightened or prolonged euphoric effects.5 Combining other mind-altering substances, especially those that also depress the central nervous system (e.g., alcohol, benzodiazepines), with opioids can increase an individual’s risk of overdose and resultant health complications.

American’s High Rate of Addiction to Opioids

USA shaped pill holder full of pills sitting on american flagASAM reports that around 2 million Americans struggled with addiction to prescription pain relievers, while more than a half-million battled heroin addiction in 2015.16

Someone dies from an opioid overdose every 19 minutes in the U.S.17 Sixty percent of the nearly 50,000 overdoses in the United States in 2014 involved an opioid drug, and more people died from a drug overdose than any other accidental means, including car crashes.18

Heroin accounted for more than 20 percent of all illicit drug-related emergency department (ED) visits in 2011, according to the Drug Abuse Warning Network (DAWN), while pain relievers were involved in just over 46 percent of ED visits from the nonmedical use of pharmaceuticals. As published by DAWN, more than 250,000 people received emergency medical care at an ED for heroin-related issues, while close to 500,000 did so for prescription opioid-related issues.19

Opioid Addiction: Treatment is Possible

For many, addiction is a chronic condition with a potential range of issues that extend beyond those of physical dependence, withdrawal symptoms, and possible health complications. When a person battles drug addiction, their emotional health, behaviors, actions, and interpersonal relationships are impacted.

Addiction can cause a person to lose control over their drug use and keep using drugs despite awareness of the potential consequences that will result. Employment, grades, and finances may be negatively affected, and legal consequences may be the result of actions perpetuated due to opiate intoxication, addiction, or attempts to obtain more drugs.

Mood swings, erratic behaviors, aggression, hostility, and a lack of interest in previously important recreational and social activities can be signs of opioid addiction.8 As a result, people who struggle with addiction to opioids may not be able to keep up with family, school, and work obligations.

Fortunately, addiction is treatable. With a comprehensive addiction treatment program that includes medical detox, behavioral therapies, counseling, support groups, education, and life skills training, recovery is well within reach.



  1. Providers Clinical Support System. (2017). What Are Opiates?
  2. United Nations Office on Drugs and Crime. (2019). World Drug Report 2019: 35 million people worldwide suffer from drug use disorders while only 1 in 7 people receive treatment.
  3. Substance Abuse and Mental Health Services Administration. (2017). Key Substance Use and Mental Health Indicators in the United States: Results from the 2016 National Survey on Drug Use and Health.
  4. Coleman, J.J. (2015). Rescheduling Hydrocodone Combination Products: Addressing the Abuse of America’s Favorite Opioid. ASAM Magazine.
  5. Committee on Pain Management and Regulatory Strategies to Address Prescription Opioid Abuse. (2017). Pain Management and the Opioid Epidemic: Balancing Societal and Individual Benefits and Risks of Prescription Opioid Use. Washington, DC: The National Academies Press.
  6. Centers for Disease Control and Prevention. (2015). Today’s Heroin Epidemic.
  7. American Academy of Family Physicians. (2019). Opioid Addiction.
  8. National Institute of Drug Abuse. (2018). What are the medical complications of chronic heroin use?
  9. World Health Organization. (2018). Information sheet on opioid abuse.
  10. Purdue Pharma. (2018). Highlights of Prescribing Information: OxyContin.
  11. MedlinePlus. (2018). Opiate and opioid withdrawal.
  12. World Health Organization. (2009). Clinical Guidelines for Withdrawal Management and Treatment of Drug Dependence in Closed Settings. Geneva: World Health Organization.
  13. Centers for Disease Control and Prevention. Preventing an Opioid Overdose.
  14. National Institute on Drug Abuse. (2018). Opioid Overdose Reversal with Naloxone (Narcan, Evzio).
  15. National Alliance of State Pharmacy Associations. (2019). Naloxone Access in Community Pharmacies.
  16. American Society of Addiction Medicine. (2016). Opioid Addiction 2016 Facts & Figures.
  17. Centers for Disease Control and Prevention. (2012). CDC grand rounds: Prescription drug overdoses—A U.S. epidemic. Morbidity and Mortality Weekly Report, 13;61(1), 10-3.
  18. Centers for Disease Control and Prevention. (2016). Increases in Drug and Opioid-Involved Overdose Deaths—United States, 2010-2015. Morbidity and Mortality Weekly Report, 65(50-51), 1445-1452.
  19. Substance Abuse and Mental Health Services Administration. (2013). Drug Abuse Warning Network, 2011: National Estimates of Drug-Related Emergency Department Visits.

About The Contributor

Scot Thomas, M.D.
Scot Thomas, M.D.

Senior Medical Editor, American Addiction Centers

Dr. Thomas received his medical degree from the University of California, San Diego School of Medicine. During his medical studies, Dr. Thomas saw firsthand the multitude of lives impacted by struggles with substance abuse and addiction, motivating... Read More

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