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What Are Opioids?

Opioids are a class of drugs that include the illegal drug heroin, synthetic opioids such as fentanyl, and pain relievers available legally by prescription, such as oxycodone (OxyContin®), hydrocodone (Vicodin®), codeine, morphine, and many others. When used correctly under a health care provider’s direction, prescription pain medicines are helpful. However, misusing prescription opioids risks dependence and addiction.

Opioids, sometimes called narcotics, are a type of drug. They include strong prescription pain relievers, such as oxycodone, hydrocodone, fentanyl, and tramadol. The illegal drug heroin is also an opioid. Some opioids are made from the opium plant, and others are synthetic (man-made).

A doctor may give you a prescription opioid to reduce pain after you have had a major injury or surgery. You may get them if you have severe pain from health conditions like cancer. Some doctors prescribe them for chronic pain.

Prescription opioids can be used to treat moderate-to-severe pain and are often prescribed following surgery or injury, or for health conditions such as cancer. In recent years, there has been a dramatic increase in the acceptance and use of prescription opioids for the treatment of chronic, non-cancer pain, such as back pain or osteoarthritis, despite serious risks and the lack of evidence about their long-term effectiveness.


Prescription pain relievers are drugs prescribed by a medical professional to reduce pain. They are also known as opioid analgesics, opioid pain relievers, or prescription painkillers. Common examples include OxyContin®, Vicodin®, codeine, and fentanyl.  Although there is a role for these drugs in medicine, they can also cause substantial harm, particularly if misused (taking your prescription in ways other than prescribed or taking someone else’s prescription). Misuse and overdose from prescription pain relievers is considered a national epidemic.

In 2011, there were almost 17,000 deaths related to prescription pain relievers. New York City has also experienced the impact of this public health crisis. From 2000 to 2013, rates of overdose death from prescription pain relievers increased 256% in New York City. In 2013, about 1 New Yorker died every other day from an opioid analgesic overdose. The majority of these deaths are entirely preventable.

When the Prescription Becomes the Problem

  • More than 191 million opioid prescriptions were dispensed to American patients in 2017—with wide variation across states.1
  • There is a wide variation of opioid prescription rates across states. Health care providers in the highest prescribing state, Alabama, wrote almost three times as many of these prescriptions per person as those in the lowest prescribing state, Hawaii.1
  • Studies suggest that regional variation in use of prescription opioids cannot be explained by the underlying health status of the population.2
  • The most common drugs involved in prescription opioid overdose deaths include:
    • Methadone
    • Oxycodone (such as OxyContin®)
    • Hydrocodone (such as Vicodin®)3

To reverse this epidemic, we need to improve the way we treat pain. We must prevent abuse, addiction, and overdose before they start.

What Are the Risks of Abusing Presciption Pain Relievers?

People often think that prescription pain relievers are safer than illicit drugs, but they can be just as dangerous.

  • In addition to helping pain, opioid analgesics can make a person feel ‘high.’ This feeling can make it harder to control use.
  • They can cause drowsiness, constipation, dry mouth and nausea.
  • Prescription pain relievers can lead to a fatal overdose because they suppress breathing. An overdose is more likely when combined with alcohol or benzodiazepines (drugs such as Xanax®, Ativan® or Valium®). Some of these combinations are so powerful that a single dose can kill a new user.
  • They can slow reaction time, which can increase the risk of accidents.
  • Regular use can lead to withdrawal symptoms when stopping, such as anxiety, muscle and bone pain, diarrhea, vomiting or restless sleep. This can occur within as little as seven days of regular use.

Addiction and Overdose

Anyone who takes prescription opioids can become addicted to them. In fact, as many as one in four patients receiving long-term opioid therapy in a primary care setting struggles with opioid addiction.4,5,6 Once addicted, it can be hard to stop. In 2016, more than 11.5 million Americans reported misusing prescription opioids in the past year.1

Taking too many prescription opioids can stop a person’s breathing—leading to death.

Prescription opioid overdose deaths also often involve benzodiazepines. Benzodiazepines are central nervous system depressants used to sedate, induce sleep, prevent seizures, and relieve anxiety. Examples include alprazolam (Xanax®), diazepam (Valium®), and lorazepam (Ativan®). Avoid taking benzodiazepines while taking prescription opioids whenever possible.

Side Effects

In addition to the serious risks of addiction, abuse, and overdose, the use of prescription opioids can have a number of side effects, even when taken as directed:

  • Tolerance—meaning you might need to take more of the medication for the same pain relief
  • Physical dependence—meaning you have symptoms of withdrawal when the medication is stopped
  • Increased sensitivity to pain
  • Constipation
  • Nausea, vomiting, and dry mouth
  • Sleepiness and dizziness
  • Confusion
  • Depression
  • Low levels of testosterone that can result in lower sex drive, energy, and strength
  • Itching and sweating

What Is drug addiction?

Addiction is a chronic disease characterized by drug seeking and use that is compulsive, or difficult to control, despite harmful consequences. The initial decision to take drugs is voluntary for most people, but repeated drug use can lead to brain changes that challenge an addicted person’s self-control and interfere with their ability to resist intense urges to take drugs. These brain changes can be persistent, which is why drug addiction is considered a “relapsing” disease—people in recovery from drug use disorders are at increased risk for returning to drug use even after years of not taking the drug.

It’s common for a person to relapse, but relapse doesn’t mean that treatment doesn’t work. As with other chronic health conditions, treatment should be ongoing and should be adjusted based on how the patient responds. Treatment plans need to be reviewed often and modified to fit the patient’s changing needs.

Image of the brain's reward circuit.
Image by NIDA
The brain’s reward circuit

What happens to the brain when a person takes drugs?

Most drugs affect the brain’s “reward circuit,” causing euphoria as well as flooding it with the chemical messenger dopamine. A properly functioning reward system motivates a person to repeat behaviors needed to thrive, such as eating and spending time with loved ones. Surges of dopamine in the reward circuit cause the reinforcement of pleasurable but unhealthy behaviors like taking drugs, leading people to repeat the behavior again and again.

As a person continues to use drugs, the brain adapts by reducing the ability of cells in the reward circuit to respond to it. This reduces the high that the person feels compared to the high they felt when first taking the drug—an effect known as tolerance. They might take more of the drug to try and achieve the same high. These brain adaptations often lead to the person becoming less and less able to derive pleasure from other things they once enjoyed, like food, sex, or social activities.

Long-term use also causes changes in other brain chemical systems and circuits as well, affecting functions that include:

  • learning
  • judgment
  • decision-making
  • stress
  • memory
  • behavior

Despite being aware of these harmful outcomes, many people who use drugs continue to take them, which is the nature of addiction.

Chronic pain is an international health issue of immense importance that is influenced by both physical and psychological factors. Opioids are useful in treating chronic pain but have accompanying complications. It is important for clinicians to understand the basics of opioid pharmacology, the benefits and adverse effects of opioids, and related problematic issues of tolerance, dependence, and opioid-induced hyperalgesia.

In this article, the role of psychiatric comorbidity and the use of validated assessment tools to identify individuals who are at the greatest risk for opioid misuse are discussed. Additionally, interventional treatment strategies for patients with chronic pain who are at risk for opioid misuse are presented. Specific behavioral interventions designed to improve adherence with prescription opioids among persons treated for chronic pain, such as frequent monitoring, periodic urine screens, opioid therapy agreements, opioid checklists, and motivational counseling, are also reviewed.

Use of state-sponsored prescription drug monitoring programs is also encouraged. Areas requiring additional investigation are identified, and the future role of abuse-deterrent opioids and innovative technology in addressing issues of opioid therapy and pain are presented.

What Are Opioid Withdrawal Symptoms?

If a person cuts back or completely stops using opioid drugs after several weeks of heavy use, he or she may experience some uncomfortable physical and psychological symptoms. These symptoms are known as opioid withdrawal. Common opioid withdrawal symptoms include:

  • Anxiety
  • Agitation
  • Watery eyes
  • Muscle aches
  • Runny nose
  • Excessive sweating
  • Insomnia
  • Yawning
  • Stomach cramps
  • Diarrhea
  • Goosebumps
  • Dilated pupils
  • Nausea
  • Vomiting7





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