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Potential side effects, signs of misuse, and how to start on a path to recovery

Opioids are a chemically related class of drugs. Types of opioids include natural derivatives of the opium poppy plant, such as heroin; semisynthetic prescription pain relievers, such as oxycodone or Oxycontin (“oxy”); and synthetic opioids like fentanyl. They can be taken by mouth, injected, smoked, or snorted.

Medical providers prescribe opioids to relieve pain from advanced cancer and other illnesses and injuries. However, many people misuse or become dependent on these potent drugs, whether or not they’re obtained lawfully. Illegally manufactured fentanyl, in particular, is driving an epidemic of opioid overdoses and deaths.

Fortunately, there are effective treatments for opioid misuse or dependence. And the over-the-counter product naloxone can stop an opioid overdose and save a life. If you or a loved one is dependent on any type of opioid, it may be time to seek help.

Recovery is possible.

Opioid types and risk factors

Opioids enter the brain and cling to cellular proteins called opioid receptors, which are found in the brain and elsewhere in the body. Our brain’s opioid system is involved in behaviors related to mood, pain, reward, and impulsivity.

Opioids stimulate the brain’s reward circuits and cause a surge in dopamine, a chemical messenger that can make us feel a pleasurable “high.” This high can also make us want to take more of the drug, increasing the risk of daily use leading to dependence.

Various risk factors are associated with misusing, becoming dependent on, or overdosing on common types of opioids.

Prescription opioids 

Factors that can make using prescription opioids more dangerous or indicate misuse or dependence include:

  • Mixing prescription opioids with other substances. It’s risky to combine prescription opioids with other drugs. This is especially true for substances that make you drowsy, such as alcohol, benzodiazepines such as Valium or Xanax, muscle relaxants like Soma, and sleep aids such as Ambien.
  • Older age and health conditions. If you are over age 50, you may be at greater risk of complications, accidents, or other dangers related to misuse of prescription opioids.
  • Acting in ways that demonstrate dependence. You may be misusing prescription opioids if you are taking pills in greater amounts or more frequently than prescribed, finishing prescriptions early, using someone else’s prescription drugs, or visiting multiple doctors and pharmacies to obtain multiple prescriptions.


Fentanyl is particularly associated with fatal and nonfatal overdoses. Factors that may lead to serious harm and even death include:

  • Taking illicit drugs laced with the opioid fentanyl. Experts are concerned that virtually any drug can be mixed with fentanyl. If you take drugs without knowing what else might be in them, you may accidentally take a fatal dose of fentanyl.
  • Using drugs alone. If you use drugs when you are alone and overdose, there may be no one around who can administer naloxone.
  • Surviving a recent overdose. If you recently experienced a nonfatal overdose, you are at heightened risk of overdosing again.
  • Mixing substances. You are in grave danger of overdosing if you mix opioids with other substances, especially those that make you drowsy (e.g., alcohol; benzodiazepines such as Valium or Xanax; muscle relaxants like Soma; and sleep aids such as Ambien).
  • Injecting drugs. If you inject drugs such as fentanyl, you increase your chances of contracting hepatitis B or C, HIV, and tetanus. 

Fentanyl test strips may be used to detect the presence of this often-deadly substance in drugs obtained illegally. However, they are not 100% reliable in detecting trace amounts of fentanyl. If you see someone experiencing a fentanyl overdose, call 911 and administer naloxone, if available. Keep the person awake and on their side until first responders arrive. Learn more.


Heroin is a highly addictive opioid. Factors that make dependence on heroin more likely include:

  • Misusing prescription opioid painkillers. If you are dependent on prescription opioids, you are 40 times as likely as others to become addicted to heroin, CDC data shows.
  • Taking other drugs. If you’re dependent on cocaine, you are 15 times as likely as others to become dependent on heroin; on marijuana, three times as likely to become dependent on heroin; and on alcohol, twice as likely to become dependent on heroin.

Side effects and signs of misuse

Many opioids are potent. Pharmaceutical fentanyl, for instance, is 50–100 times as strong as morphine. Illicit fentanyl, which other drugs are sometimes laced with, is highly variable and dangerous, with stronger side effects and greater overdose risk than heroin.

Opioids mask pain and induce feelings of euphoria, intense calm, and sleepiness. Other common short-term side effects of opioids include confusion, slowed or stopped breathing, sickness and vomiting, and gastrointestinal issues such as constipation. Long-term use of these substances can cause dependence, heart and lung infections, and muscle pain.

Stopping use of opioids can cause intense, flu-like withdrawal symptoms. Preventing the onset of these ill feelings can lead to continued, long-term opioid use and dependence, a condition sometimes called opioid use disorder.

Use of opioids can lead to serious harm and even death. Consumption of illegally manufactured fentanyl — which may be sold as counterfeit prescription opioids or added to cannabis, cocaine, heroin, or methamphetamine — is driving up rates of opioid overdose and death. Heroin is also a highly addictive drug; 23% of people who use it develop a dependence on it.

These additional factors could increase your risk of misusing, becoming dependent on, or facing serious harm from opioids:

  • Age, lifestyle, and medical history. Dependence is more likely if you use or have used other drugs, have an untreated mental illness, or live in a situation that enables drug misuse. The rate of nonmedical opioid use is highest among people ages 18 to 25, and most people who misuse prescription opioids start using the drug in their early to late 20s. Prescription opioid overdose deaths occur mostly among people aged 25 to 54.
  • Long-term use. Using opioids for even a few days raises your risk of becoming dependent. An estimated 1 in 4 people receiving prescription opioids long term in a primary care setting become dependent, according to research summarized by the Centers for Disease Control and Prevention (CDC).
  • High dosage. Taking a higher dose comes with a greater risk of dependence than taking a lower dose does, but even taking a low dose is risky, according to CDC prescribing guidelines.
  • Extended-release formulations. Dependence is more common with drugs that act over a longer period than with those that act more immediately, CDC guidelines say.

Naloxone can stop an opioid overdose and save a life. If you or someone you know is using opioids, carry naloxone, a medication available over the counter without a prescription that can safely reverse the toxic effects of an overdose. Learn more.

Withdrawal symptoms and signs of overdose

In the case of prescription and other opioids, experts recommended that you slowly taper off and stop use of these drugs under the care of a medical provider, who can help you manage any withdrawal symptoms. Withdrawal can start within eight hours and last as long as 20 days. Slowed or stopped breathing is a sign of an opioid overdose. If you see someone with these symptoms, call 911 and administer naloxone if you have it available. Naloxone used in this way is generally safe, even if it’s mistakenly administered to a person who is not experiencing an overdose.

These drugs are also associated with specific withdrawal symptoms, which can start within a few hours of stopping use of the substance. They may include cold flashes and goose bumps, watery eyes, runny nose, diarrhea and vomiting, bone and muscle pain, uncontrolled leg movements, severe cravings, irritability, yawning, and sleep difficulties.

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Treatment for misuse  

Recovery from opioid misuse and dependence is possible. Behavioral therapies can reduce the potential for relapse, and prescription medications can lessen withdrawal symptoms.

Therapy: A licensed medical provider may recommend medication for addiction treatment (MAT), which combines the use of prescription drugs to alleviate withdrawal symptoms with therapies such as behavioral counseling. Studies have shown that MAT reduces opioid use and related deaths. Types of counseling to treat dependence on fentanyl and other opioids include cognitive behavioral therapy; contingency management, which assigns “points” for negative drug tests; and motivational interviewing, which is a form of patient-focused counseling. The Food and Drug Administration (FDA) has also authorized a mobile cognitive behavioral therapy app called reSET that can be used with MAT and other therapies; the app is available by prescription.

Medications: Specific FDA-approved opioid use treatments include buprenorphine (brand names include Suboxone and Subutex); methadone; and extended-release naltrexone (marketed as Vivitrol). The FDA has also approved the nonopioid treatments clonidine and lofexidine (sold under the brand names Catapres and Lucemyra, respectively) for managing opioid withdrawal. Use these medications with caution, as they can cause low blood pressure. Until you’re fully recovered from opioid use dependence, carry naloxone, an over-the-counter nasal spray that can reverse opioid overdose.

Recovery: Further manage your symptoms and promote your recovery by drinking a lot of water, getting plenty of exercise, and practicing relaxation techniques such as yoga and meditation.

Find Support


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