Drugs and Substances: Learn It 4—Opioids

Opioids

opioids

Opioids are a class of drugs that include natural, semi-synthetic, and fully synthetic compounds such as Morphine, Codeine, Methadone, Fentanyl, and the illicit drug Heroin. These drugs act on opioid receptors in the brain and body—somewhat like the body’s own small quantities of endogenous opioid compounds—reducing pain and often producing euphoria. Because of this, opioid drugs carry a high potential for misuse and problematic use.

Many prescription pain-relievers today (such as Oxycodone and Hydrocodone) are synthetic or semi-synthetic opioids with strong effects.

Natural opioids, called opiates, are derivatives of opium, which is a naturally occurring compound found in the poppy plant.

 

Aside from their utility as analgesic drugs, opioid-like compounds are often found in cough suppressants, anti-nausea, and anti-diarrhea medications. 

Opioid Abuse

There are several synthetic versions of opiate drugs (called opioids) that have very potent painkilling effects, and they are often abused. These include prescription painkillers hydrocodone, oxycodone, and fentanyl.

The Opioid Epidemic

The opioid epidemic, or the opioid crisis, refers to the extensive overuse of opioid drugs, both from medical prescriptions and from illegal sources. The epidemic began in the United States, starting slowly in the late 1990s, eventually leading to a massive increase in opioid use in recent years, contributing to over 70,000 drug overdose deaths in the U.S. in 2018 and over 80,000 deaths in 2021. Fentanyl alone, being 50 times stronger than heroin and 100 times stronger than morphine, was causing about 200 overdose deaths per day in 2017.[1]. 2024 was the first year with declining numbers of overdose deaths in the United States since 2020.[2]

Opioids are a diverse class of moderately strong, addictive, inexpensive painkillers prescribed by doctors. Initially, pharmaceutical companies reassured the medical community that patients would not become addicted to opioid pain relievers, leading to widespread prescriptions. However, they turned out to be highly addictive.

Over time, people have shifted from prescription opioids to illegal ones like heroin and fentanyl, especially as prescriptions became harder to get. Studies show that most opioid abusers started with a legal prescription but later turned to illegal sources.[3]

Those addicted to opioids, both legal and illegal, are increasingly young, White, and female, with 1.2 million women addicted compared to 0.9 million men in 2015. The populations of rural areas of the country have been the hardest hit. Teen abuse of opioids has been noticeably increasing since 2006, with prescription drugs being used more than any illicit drug except marijuana; more than cocaine, heroin, and methamphetamine combined. The crisis has also changed many people’s moral, social, and cultural resistance to street drug alternatives such as heroin, with individuals often turning to street drugs once they are no longer able to secure a prescription opioid source.

Fentanyl, due to extreme potency and widespread misuse, is particularly problematic. It is often mixed, cut, or ingested alongside other drugs, including cocaine and heroin. Mixing with other drugs or disguising as a pharmaceutical makes it difficult to determine the correct treatment in the case of an overdose, resulting in even more deaths. 

Heroin Abuse

Historically, heroin was a majorly abused opioid drug. It is still abused (snorted, smoked, injected), but many users now transition from prescription opioids to heroin to fentanyl-laced products.

Heroin produces intense feelings of euphoria and pleasure, which are amplified when the heroin is injected intravenously. Following the initial “rush,” users experience 4–6 hours of “going on the nod,” alternating between conscious and semi-conscious states. Some people who have injected many times into their arms will show “track marks,” while other users will inject into areas between their fingers or between their toes, so as not to show obvious track marks. Like all abusers of intravenous drugs, heroin users have an increased risk of contracting both tuberculosis and HIV.

Photograph A shows various paraphernalia spread out on a black surface. The items include a tourniquet, three syringes of varying widths, three cotton-balls, a tiny cooking vessel, a condom, a capsule of sterile water, and an alcohol swab. Photograph B shows a hand holding a spoon containing heroin tar above a small candle.
Figure 1. (a) Common paraphernalia for heroin preparation and use are shown here in a needle exchange kit. (b) Heroin is cooked on a spoon over a candle. (credit a: modification of work by Todd Huffman)

Opioid Withdrawal

Given that withdrawal from a drug often involves an experience opposite to the effect of the drug, it should be no surprise that opioid withdrawal resembles a severe case of the flu.

While intensely uncomfortable, opioid withdrawal is generally not life-threatening for healthy adults; however, risks increase when the use/health status is complex. (In contrast, withdrawal from alcohol or benzodiazepines can be life-threatening.

Medications to help those experiencing opioid withdrawal include Methadone (full agonist), Buprenorphine (partial agonist), and Naltrexone (antagonist). These reduce overdose risk, support recovery, and are endorsed by clinical guidelines.

  1. Fentanyl As A Dark Web Profit Center, From Chinese Labs To U.S. Streets", KUAR, NPR Radio News, Sept. 4, 2019 ↵
  2. Centers for Disease Control and Prevention. (2025, June 9). Understanding the opioid overdose epidemic. U.S. Department of Health & Human Services. https://www.cdc.gov/overdose-prevention/about/understanding-the-opioid-overdose-epidemic.html ↵
  3. Prescription Opioid Data". Centers for Disease Control and Prevention (CDC). ↵