Opiates are compounds derived directly from the Papaver somniferum plant (poppy plant), while opioids are synthetic and semisynthetic compounds with similar biochemical properties. Opioid drugs include morphine and codeine (natural opiates); heroin, oxycodone, oxymorphone, hydrocodone, hydromorphone, and buprenorphine (semisynthetic opioids); and meperidine (Demerol), fentanyl and fentanyl analogs such as carfentanyl, and methadone (synthetic opioids). Common routes of drug administration include oral, inhalation (smoking), intranasal (snorting), subcutaneous (skin popping), and intravenous (IV).

Opioids are effective in treating pain; however, their use does not come without risks. In addition to their analgesic properties, opioids activate the reward pathway in the brain, causing a euphoria or "high." Regular, repeated use of opioids leads to tolerance and dependence. Unfortunately, at high doses or when combined with other substances, opioids can cause potentially fatal respiratory depression (see opioid overdose). Prior to prescribing opioids, health care providers should carefully consider their associated risks and benefits. Resources for opioid prescribing guidelines, as well as nonopioid alternatives, can be found here.

Per the US Centers for Disease Control and Prevention (CDC) website, in the United States, the first wave of opioid overdose deaths involved prescription opioids and began with increased prescribing of opioids in the 1990s. This was followed by abuse and fatalities associated with the proliferation of nonprescription opioids. The opioid epidemic continues to evolve in the United States – per the CDC, the US is currently in the third wave of opioid overdose deaths, as the majority of overdose deaths are now attributable to synthetic opioids, such as fentanyl, as opposed to heroin or prescription opioids. In 2019, the National Survey on Drug Use and Health estimated 1.6 million people (aged 12 and older) in the United States meet the criteria for opioid use disorder (OUD).

Patients who are physiologically dependent on opioid pain medications and unable to obtain prescriptions legally may pursue opioids through alternate means. Persons using diverted opioids or street drugs face a greater risk of overdose and death due to inconsistency of strength / dosage, drug interactions, or contamination of supply.

Opioid withdrawal syndrome may present with profuse sweating, hypertension, nausea, vomiting, fever, anxiety, and lacrimation. The severity of withdrawal symptoms can be quantified using the Clinical Opiate Withdrawal Scale (COWS). For discussion of withdrawal symptoms in neonates due to maternal use of opioids during pregnancy, see neonatal abstinence syndrome.

Note: Patients with substance use disorder (SUD) are at an increased risk of suicide, and children of parents with SUDs are at increased risk for neglect and/or abuse.