Skip to Main Content

Public Health

Vetted resources and information on current public health events.

What are Opioids?

Opioids are a class of drugs naturally found in the opium poppy plant. Some opioids are made directly from the plant, while others (synthetic) are created in a lab by scientists to mimic the same structure and and properties of the natural plant.

The opioid drug class contains both legal prescription pain medications as well as illegal street drugs. However, many legal prescription pain medications such as fentanyl, which is a synthetic opioid, can be created illegally created in drug labs and sold as street drugs.

Types of Opioids
  • Natural opiates - drugs derived from the opium poppy plant, including prescription drugs such as morphine and codeine
  • Semi-synthetic opioids - man-made opioids created in a lab from natural opiates, including prescription drugs such as oxycodone, hydrocodone, hydromorphone, and oxymorphone; the illegal drug heroin is also a semi-synthetic opioid made from morphine
  • Synthetic opioids - prescription drugs such as methadone, tramadol, fentanyl, and buprenorphine
Opioids vs Opiates
  • Opioids refer to all natural, semi-synthetic, and synthetic opioids
  • Opiates refer only to natural opioids such as heroin, morphine and codeine

Prescription Opioids

Opioids are used to manage acute and chronic pain (including cancer pain). They work by releasing chemicals that relax the body and relieve pain. Opioids are usually only prescribed to treat moderate to severe pain, such as post-operative pain and chronic pain from diseases like cancer and sickle cell disease.

Commonly Prescribed Opioids:
  • hydrocodone/acetaminophen (Vicodin®)
  • oxycodone (OxyContin®
  • oxycodone/acetaminophen (Percocet®)
  • oxymorphone (Opana®)
  • morphine (Kadian®, Avinza®)
  • codeine
  • fentanyl

Opioid Prescription Misuse

Prescription opioids are generally safe to take when prescribed by your doctor for a short time, however they can quickly and easily become misused in various ways:

  • taking the medication in a way or dose other than what was prescribed by your doctor
  • taking someone else's medication
  • taking the medication for the effect it causes - to get high

Opioids can be used for non-medical reasons, to get "high". Because opioids are extremely dangerous to take without a prescription and are highly addictive, doctors must carefully monitor patients on opioid therapy to prevent opioid misuse.

Opioid Tolerance

Tolerance is when a therapy's effectiveness becomes reduced. Opioid tolerance occurs when patients are prescribed opioids long-term, and eventually the effectiveness of the current dosage no longer relieves the pain. As tolerance increases, patients require higher doses to achieve the same level of pain management.

If patients are not adequately monitored by their doctors, this opioid tolerance can lead to the patient misusing their prescription.

Opioid Dependence

Dependence is when the body adjusts how it functions around the drug usage and can often lead to unpleasant symptoms if the drug is stopped.

Opioid Addiction

Drug addiction, or opioid use disorder (OUD) usually occurs after opioid tolerance and opioid dependence, when it becomes physically challenging to stop drug usage, and attempts are often unsuccessful.

Other Commonly Used Terms

What is the Opioid Epidemic?

The opioid epidemic is defined as the rise in opioid-related overdoses and deaths, with the increases starting since at least 1999. There are 3 distinct waves of the opioid epidemic.

Wave 1: Prescription Opioid Drug Overdoses

Each year millions of Americans are prescribed opioid pain medications to treat acute and chronic pain and other conditions. Medical prescriptions for opioids started to increase sharply in the mid-to late 1990s. Not surprisingly, considering the highly addictive nature of opioids, beginning in 1999 non-medical opioid use also started to increase markedly.

From 1999 to 2011, hydrocodone use increased more than two-fold, oxycodone use more than five-fold, and opioid-related overdose deaths increased four-fold. Overdose mortality is the most dramatic consequence of increased opioid use, but it is not the only one; rates of emergency room visits for non-medical opioid use, neonatal abstinence syndrome (NAS), and OUD treatment admissions all have soared since 2002 (Trends in Opioid Use, Harms, and Treatment, 2017)

Wave 2: Heroin Overdoses


Wave 3: Fentanyl Overdoses

Opioid Overdose Statistics

Opioid Overdose Deaths

The number of drug overdose deaths increased by nearly 30% from 2019 to 2020 and has quintupled since 1999.  Nearly 75% of the 91,799 drug overdose deaths in 2020 involved an opioid. From 2019 to 2020, there were significant changes in opioid-involved death rates:

From 1999–2020, more than 564,000 people died from an overdose involving any opioid, including prescription and illicit opioids.

Changes in Opioid Overdose Deaths, 2019-2020
Prescription Opioids




Synthetic Opioids

Opioid Overdose Resources