Analgesics, opioid

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Editor: Jacqueline L. Longe
Date: Apr. 4, 2018
Publisher: Gale, a Cengage Company
Document Type: Drug overview
Length: 1,724 words

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Opioid analgesics are synthetic narcotic pain relievers similar to naturally occurring opiates such as morphine and heroin that contain or are derived from the Asian poppy Palaver somniferous. However, all narcotics are often referred to as opioids. Opioids act on the central nervous system (CNS) and can be addictive.

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In the past, opioid analgesics, with the exception of codeine (usually manufactured from morphine sap), were generally prescribed in the United States only for conditions such as terminal cancer pain. However, beginning in the 1990s, opioids began to be prescribed to relieve pain from a wide variety of conditions, out of justifiable concern that pain was being undertreated, as well as targeted marketing campaigns by certain pharmaceutical companies. By the early twenty-first century, opioids were being prescribed before, during, and after surgeries (including dental surgeries) and during labor and delivery, as well as for diabetic neuropathy, lower back pain, headaches, injuries, and various chronic diseases and disorders. Soon U.S. healthcare providers were writing about 250,000 million opioid prescriptions annually. Because of widespread opioid addiction, the prescribing indication was revised to read: “For the management of pain severe enough to require daily, around-the-clock, long-term opioid treatment and for which alternative treatment options are inadequate.”


Opioid analgesics relieve pain by binding to opiate receptors on cells of the CNS. They are often combined with non-narcotic painkillers such as aspirin, acetaminophen, or non-steroidal anti-inflammatory drugs. Opioid analgesics come in many forms—tablets, syrups, suppositories, and injections. They are sold only by prescription. Federal regulations prohibit refills of some opioids. Opioids also may require that a physical prescription be brought to the pharmacy rather than having the prescription called or faxed in by the physician. In 2017, in response to accusations of opioid profiteering, CVS pharmacies announced that opioid prescriptions for acute or new conditions would be limited to seven days, and that daily dosages would be limited for all opioid prescriptions. Furthermore, immediate-release formulations must be prescribed before extended-release formulations that are more susceptible to abuse. A number of states already had similar restrictions in place.

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Key Terms

Medicine used to relieve pain.
Central nervous system (CNS)
The brain and spinal cord.
Inflammation of the colon (large bowel).
A false or distorted perception of objects, sounds, or events that seems real. Hallucinations usually result from drugs or mental disorders.
Drugs derived from or similar to opium that are potent pain relievers, can affect mood and behavior, and can lead to tolerance and dependence.
A drug containing or derived from opium—such as codeine, morphine, or heroin—that alleviates pain and induces sleep.
A decrease in sensitivity to a drug that requires taking more of the drug to achieve the same effect.
Physical and/or mental symptoms that can occur when suddenly stopping a drug.

U.S. brand names

U.S. brand names for some opioid analgesics include:

  • Actiq, Duragesic, Fentora, Ionsys, Lazanda, Onsolis, Subsys (fentanyl)
  • Anexsia, Lortab, Vicodin (hydrocodone combined with acetaminophen)
  • Buprenex, Subutex (buprenorphine)
  • Dazidox, OxyContin, Oxydose, Oxyfast, Roxicoson (oxycodone)
  • Demerol, Meperitab (meperidine)
  • Dilaudid, Exalgo, Palladone (hydromorphone)
  • Dolophine, Methadose (methadone, a heroin substitute without psychoactive effects)
  • Duramorph, MS Contin, Roxanol (morphine)
  • Numorphan, Opana (oxymorphone)
  • Percocet, Roxicet (oxycodone combined with acetaminophen)
  • Percodan (oxycodone plus aspirin)
  • Ultram (tramadol)
  • Zohydro ER (hydrocodone)

Canadian brand names

Canadian brand names for some opioid analgesics include:

  • Atasol, Tylenol (codeine with acetaminophen and caffeine)
  • Codeine Contin (codeine)
  • Darvon-N (propoxyphene napsylate)
  • Demerol (meperidine)
  • Dilaudid, Hydromorph Contin (hydromorphone)
  • Duragesic (transdermal fentanyl)
  • Empracet (codeine plus acetaminophen)
  • Endocet, Percocet (oxycodone with acetaminophen)
  • Kadian, Statex (morphine)
  • Metadol (methadone)
  • OxyContin, Oxy-IR, Supeudol (oxycodone)
  • Ralivia, Zytram XL (tramadol)
  • Talwin (pentazocine)
  • Tramacet (tramadol/acetaminophen)

Recommended dosage

Recommended dosages vary depending on the type and strength of the opioid analgesic and the form in which it is being used. Doses also may depend on the patient’s size, age, and physical condition. People should check with their physician or pharmacist for correct dosages and make sure they understand how to take the drug. Opioid analgesics should not be stopped suddenly without checking with the prescribing physician or dentist. Gradually tapering (lowering) the dose may reduce the risk of withdrawal symptoms.


Opioid analgesics should always be taken exactly as directed—never in larger or more frequent doses or for longer than prescribed. Opioid analgesics—or any narcotic—can lead to dependence and addiction. Physical dependence can cause withdrawal symptoms if the drug is stopped. Buprenorphine or naltrexone can prevent withdrawal symptoms, as well as help treat opioid addiction. Tolerance to opioid analgesics can develop over time, so that larger and larger doses are required to achieve the same level of pain relief. Prescription drugs should never be shared with others. Patients should be aware that some opioid analgesics also contain aspirin, acetaminophen, or caffeine.

As of 2017, an estimated two million Americans suffered from prescription opioid abuse disorder or addiction, and another 591,000 suffered from heroin addiction, which often begins with the use of prescription opioids for pain. As people addicted to prescription opioids such as oxycodone turned to cheaper and more easily obtained heroin, deaths from heroin increased 328% between 2010 and 2015. Between 1999 and 2017, some 200,000 Americans died of overdoses involving oxycodone and other prescription opioids. Approximately 64,000 Americans died of drug overdoses in 2016—a 21% increase over 2015. As of 2017, an estimated 145 Americans were dying of opioid overdoses every day. Although naloxone (Narcan) can reverse opioid overdose, the epidemic strained emergency services, hospitals, and morgues and relegated an additional 30,000 children to foster care nationwide between 2012 and 2015.


Children are especially sensitive to opioid analgesics, which can cause restlessness, agitation, or serious breathing problems in children. Nevertheless, in 2015 the U.S. Food and Drug Administration (FDA) granted approval for the marketing of OxyContin to children as young as 11.


Like children, geriatric patients are highly sensitive to opioid analgesics and may experience serious breathing problems.

Pregnant or breastfeeding

Use/misuse of opioid analgesics during pregnancy puts newborns at risk for neonatal opioid withdrawal syndrome. In the United States in 2017, an opioid-addicted baby was born every 30 minutes; in some parts of the country, 10% of newborns are opioid-dependent. If taken just before delivery, some opioid analgesics may cause serious breathing problems in newborns.

Some opioid analgesics can pass into breast milk and may affect the nursing baby. Breastfeeding women should check with their physicians before taking opioid analgesics.

Other conditions and allergies

Patients should inform their prescriber of any allergies to food, dyes, preservatives, or other substances and any previous reactions to opioid analgesics. The following conditions can alter the effects of opioid analgesics:

  • head injury
  • history of convulsions
  • asthma, emphysema, or any chronic lung disease
  • heart disease
  • kidney disease
  • liver disease
  • underactive thyroid, which can increase the risk of side effects
  • Addison’s disease (a disease of the adrenal glands)
  • colitis
  • gallbladder disease or gallstones
  • enlarged prostate or other urinary problems
  • current or past alcohol abuse
  • current or past drug abuse, especially narcotic abuse
  • current or past emotional problems, which can increase the risk of side effects

Side effects

Some people experience drowsiness, dizziness, lightheadedness, or a false sense of well-being after taking opioid analgesics. People taking opioids should not drive, use machinery, or perform any potentially dangerous activities until they know how the drug affects them. Nausea and vomiting are other common side effects, especially when first taking opioid analgesics. If these symptoms do not go away after the first few doses, the prescriber should be notified.

Dry mouth is common side effect. Dry mouth can be relieved by sucking on sugarless hard candy or ice chips or by chewing sugarless gum. Saliva substitutes, which come in liquid or tablet forms, also may help. Patients who must use opioid analgesics over long periods and who have dry mouth should see their dentists, as this can lead to tooth decay and other dental problems.

The following side effects may be signs of an overdose and require emergency medical assistance:

  • cold, clammy skin
  • bluish discoloration of the skin
  • extremely small pupils
  • serious difficulty breathing or extremely slow breathing
  • extreme sleepiness or unresponsiveness
  • severe weakness
  • confusion
  • severe dizziness
  • slow heartbeat
  • low blood pressure
  • severe nervousness or restlessness

The following less common side effects require medical attention:

  • hallucinations or a sense of unreality
  • depression or other mood changes
  • ringing or buzzing in the ears
  • pounding or unusually fast heartbeat
  • itching, hives, or rash
  • facial swelling
  • trembling or twitching
  • dark urine, pale stools, or yellow eyes or skin (after taking propoxyphene)
  • increased sweating or red or flushed face (more common with hydrocodone and meperidine)

The following side effects usually disappear after the first few doses; if they continue or interfere with normal activities, patients should check with their prescribing physician:

  • headache
  • loss of appetite
  • restlessness or nervousness
  • nightmares, unusual dreams, or problems sleeping
  • weakness or fatigue
  • mental sluggishness
  • stomach pain or cramps
  • blurred or double vision or other vision problems
  • problems urinating, such as pain, difficulty urinating, frequent urge to urinate, or decreased amount of urine
  • constipation


Alcohol should be avoided as it increases the side effects of opioid analgesics—including drowsiness, dizziness, breathing problems, nausea, and dependence. In 2016, the FDA issued strong new warnings that combining opioid medications and benzodiazepines (antianxiety drugs such as Ativan and Xanax) can suppress breathing and lead to coma or death. In addition, patients taking any of the following medications should notify their physician before taking opioid analgesics:

  • CNS depressants, such as antihistamines and other medicines for allergies, hay fever, or colds; tranquilizers; some other prescription pain relievers; seizure medicines; muscle relaxants; sleeping pills; some anesthetics (including dental anesthetics)
  • monoamine oxidase (MAO) inhibitors, such as phenelzine (Nardil) and tranylcypromine (Parnate), which are particularly dangerous in combination with meperidine
  • tricyclic antidepressants, such as amitriptyline (Elavil)
  • anti-seizure medicines, such as carbamazepine (Tegretol), which may lead to serious side effects, including coma, when combined with propoxyphene
  • muscle relaxants, such as cyclobenzaprine (Flexeril)
  • sleeping pills, such as triazolam (Halcion)
  • blood-thinning drugs, such as warfarin (Coumadin)
  • naltrexone (Trexan, Revia), which counters the effects of opioid analgesics
  • rifampin (Rifadin)
  • zidovudine (AZT, Retrovir), which has serious side effects when combined with morphine

Opioids may interact with certain herbal preparations sold as dietary supplements, including valerian (Valeriana officinalis), ginseng (Panax ginseng), kava kava (Piper methysticum), and chamomile (Matricaria chamomilla). Patients should inform their doctors of any herbal remedies that they take on a regular basis, along with a list of their other prescription medications.

Disclaimer:   This information is not a tool for self-diagnosis or a substitute for professional care.

Source Citation

Source Citation   (MLA 8th Edition)
Ross-Flanigan, Nancy, et al. "Analgesics, opioid." The Gale Encyclopedia of Medicine, edited by Jacqueline L. Longe, 5th ed., Gale, 2015. Gale Health and Wellness, Accessed 13 Dec. 2019.

Gale Document Number: GALE|TAYMRV254231791