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Drug Overdose Symptoms, Treatment, and Prevention

A drug overdose occurs when a person takes enough of a drug that it results in a life-threatening reaction or death.1 A drug overdose is a medical emergency. If you think that you or another person are currently experiencing an overdose, it is critical to call 911 immediately.

This article will help you learn more about drug overdose, including:

  • Drug overdose symptoms.
  • How to prevent a drug overdose.
  • How a drug overdose is treated.
  • Getting treatment for drug misuse and addiction.

What Is a Drug Overdose?

A drug overdose occurs when a person takes enough of a drug that it results in a life-threatening reaction or death.1 A drug overdose can be intentional, such as in instances of self-harm, or unintentional if a person:2

  • Takes a drug accidentally.
  • Takes too much of a drug accidentally.
  • Engages in polysubstance use (e.g., combining 2 or more drugs, such as alcohol and benzodiazepines).

A drug overdose can be life-threatening and can even be fatal, with synthetic opioids like fentanyl accounting for the majority of overdose dose deaths.3 In 2020, nearly 92,000 people died from a drug overdose in the U.S., of which 75% involved opioids and 82.3% of opioid-involved deaths involved synthetic opioids like fentanyl.3

Even when a drug overdose isn’t fatal, it can have short- and long-term health consequences. Furthermore, people who experience an overdose are more likely to overdose again in the future.4

Signs and Symptoms of a Drug Overdose

The signs and symptoms of a drug overdose can range from mild to severe and vary depending on the drug taken and how much, the route of administration (e.g., ingesting, inhaling, or intravenously), and whether a person took other substances at the same time, including over the counter and prescription medication.5

Learn more about substance-specific overdose signs and symptoms below.


An alcohol overdose occurs when the level of alcohol in a person’s bloodstream is so significant that areas of the brain controlling certain life-preserving functions begin to shut down.6 As a person’s blood-alcohol content (BAC) rises, so does the risk of alcohol overdose.6 The risk of alcohol overdose is greater in people who engage in binge drinking or who drink to a BAC above 0.08.6 An alcohol overdose can lead to coma, death, or permanent brain damage if a person doesn’t receive the help they need.6

The potential signs and symptoms of an alcohol overdose include:6

  • Confusion.
  • Sleepiness.
  • Difficulty remaining conscious.
  • Vomiting.
  • Dulled responses (e.g., no gag reflex).
  • Blue, pale, or clammy skin.
  • Irregular or slowed breathing.
  • Decreased blood pressure, heart rate, and temperature.
  • Seizures.


Opioids are a class of drugs that include legal prescription medications like oxycodone and hydrocodone, and illicit drugs like heroin.7 Opioid overdose deaths have been on the rise for over 2 decades. Between 2019 and 2020, opioid-involved death rates increased by 38% while synthetic opioid-involved (e.g., fentanyl) death rates increased by 56%.8

Most opioid overdose deaths involve fentanyl, a synthetic opioid sometimes prescribed to treat severe pain.9 While fentanyl may be legally obtained by a prescription, it’s often illicitly manufactured and distributed through drug markets where it is either sold for its heroin-like effects or mixed in with other drugs, including counterfeit pills. Fentanyl can be 50 times more potent than heroin and 100 times more potent than morphine. This makes the drug cheaper, which is why it’s often added to other drugs.9 The Centers for Disease Control and Prevention (CDC) report that over 150 people die every day from overdoses related to synthetic opioids like fentanyl.9

When a person overdoses on opioids, their breathing can slow or stop, resulting in the brain not getting enough oxygen, leading to coma, death, or permanent brain damage. Signs and symptoms of an opioid overdose include:10, 11

  • Small pupils.
  • Loss of consciousness.
  • Slow, shallow breathing.
  • Vomiting.
  • Choking or gurgling sounds.
  • Limp body.
  • Cold, pale skin.
  • Purple fingernails and lips.

Naloxone (e.g., Narcan, Kloxxado, RiVive) is a life-saving medication that can reverse the effects of an opioid overdose. If you have naloxone and suspect an opioid-involved overdose, you should administer it as soon as possible and call 911, as naloxone can wear off while opioids may remain in the body causing overdose symptoms to reemerge.12


Sedatives are central nervous system (CNS) depressants that work to inhibit or decrease CNS activity.13, 14 Sedatives include a range of prescription medications used to treat anxiety and panic disorders, sleep disorders, and acute stress reactions.13, 14 The class of drugs includes several types of medications, including barbiturates, benzodiazepines, and prescription sleep medications.13, 14

Signs of a sedative overdose can include:13

  • Slurred speech.
  • Nystagmus (e.g., involuntary eye movements).
  • Impaired coordination.
  • Ataxia (e.g., poor muscle control).
  • Impaired memory.

Severe sedative overdoses can cause respiratory depression, potentially resulting in hypoxia, a condition in which the brain doesn’t receive enough oxygen. Hypoxia can lead to permanent brain damage, coma, and death.14 While an isolated sedative overdose rarely causes respiratory depression, combining them with other substances like alcohol, other CNS depressants, or opioids increases the risk of experiencing a life-threatening overdose.15 Combining sedatives with stimulants is also risky, as stimulants can be unpredictable when combined with sedatives, including masking certain effects of an overdose that may continue or return when the stimulant wears off.


Stimulants are a class of drugs that increase central nervous system (CNS) activity by interacting with dopamine, norepinephrine, and other neurotransmitter systems.16 This can make a person feel more alert and energetic, among other effects.16 Stimulants include legal substances such as caffeine and prescription amphetamines (e.g., Adderall) and other medications (e.g., Ritalin) used to treat ADHD and illegal substances such as cocaine and crystal methamphetamine.16

Unintentional death from stimulant use or overdose can occur, in part, because stimulants affect the body’s cardiovascular- and temperature-regulating systems. Stimulant overdose symptoms vary, but people commonly experience:16, 17

  • Restlessness.
  • Tremor.
  • Overactive reflexes.
  • Aggression.
  • Confusion.
  • Panic.
  • Fever.
  • Chest pain and irregular heart rhythms (arrhythmias).
  • Cardiovascular collapse.


The term ‘inhalants’ refers to substances taken only by inhaling.18 These include aerosol sprays, gases, nitrates, and solvents. Various products found in the home or workplace (e.g., computer cleaning products, glue, markers, and spray paint) can contain dangerous substances that increase inhibitory tone in the CNS and produce short-term effects similar to alcohol, such as dizziness, euphoria, and impaired coordination.18

Because any euphoric effects last just a few minutes, many people use inhalants repeatedly over a few hours to maintain the effects.17 This can increase the risk of overdose, leading to coma or death. Repeated inhalation can lead to high concentrations of inhalant fumes in the lungs, which can replace oxygen and cause asphyxiation. Even if a person uses inhalants just once, “sudden sniffing death” can occur.17, 18


Marijuana comes from the Cannabis sativa plant and contains delta-9 tetrahydrocannabinol (THC), the primary psychoactive chemical responsible for many of the drug’s intoxicating properties.19 People ingest marijuana in several ways, such as by smoking it in bongs, joints, or pipes, or consuming it in food. Marijuana can also be infused into several food products, often referred to as edibles.19

Currently, there are no reports of death from using marijuana alone.19 However, some people report experiencing uncomfortable effects from marijuana use, especially when using marijuana products with high levels of THC. Emergency department staff have reported an increase in cases involving marijuana edibles, which generally take longer for the effects to be felt when compared to smoking, which can lead to consuming more of the product. Edibles generally have longer-lasting intoxicating effects and can be unpredictable.19, 20

Polysubstance Use Increases the Risk of Overdose

The term polysubstance use refers to the use of more than 1 substance at the same time.21, 22 Polysubstance use can include combining 2 or more substances from the same drug classification (e.g., a depressant and a depressant) or different drug classifications (e.g., a depressant and a stimulant). Polysubstance use can also include combining illicit drugs (e.g., cocaine and heroin). The dangers of polysubstance also apply to alcohol, prescription medication, and tobacco.21, 22

No matter the combination, all instances of polysubstance use are dangerous and can have significant consequences, including an increased risk of life-threatening overdose.22 Unfortunately, polysubstance use is common. Data suggest that most people who die from an overdose have multiple substances in their system.23

Polysubstance use can be intentional or unintentional if a person uses a substance that is unknowingly laced or mixed with another substance. Purchasing illicit substances or prescription drugs, which are often counterfeit, off the streets increases the likelihood of taking unknown substances, which increases the risk of overdose and death.24

There is also an increased risk of fentanyl contamination of illegal drugs. Illicitly manufactured fentanyl is often mixed into other drugs like cocaine, heroin, and methamphetamine. This can increase the risk of overdose among people who may not be aware this potentially life-threatening additive is present.25

What to Do in Case of An Overdose

It’s not always easy to tell if someone is experiencing an overdose. However, if you aren’t sure, you can save a life by treating it like an overdose. In the event of an overdose or suspected overdose:26

  • Call 911 immediately.
  • Administer naloxone (Narcan, Kloxxado, RiVive) if you have it.
  • Keep the person awake.
  • Lay the person on their side, which can prevent choking.
  • Remain with the person until emergency personnel arrives.

Although naloxone is only effective in reversing the effects of opioids, if you have access to naloxone, it should be administered, even if you’re not sure if a person is overdosing on opioids. Illicitly manufactured fentanyl, a highly potent opioid, is regularly found as an adulterant in all types of illicit drugs and counterfeit prescription drugs. Naloxone won’t harm a person if they’re overdosing on drugs other than opioids.26

The Centers for Disease Control and Prevention (CDC) reports that someone else was present in nearly 40% of overdose deaths.26 If you’re worried about getting in legal trouble, know that most states have Good Samaritan laws that protect a person who is overdosing and the person who called for help.26

Overdose Prevention

An overdose can happen to anyone, and knowing how to prevent and manage drug overdoses can save your life or someone else’s life:27, 28

  • Don’t wait to get treatment. If you are concerned about your or a loved one’s drug use, don’t wait to get help. Professional treatment can reduce the risk of overdose and help people struggling with drug use live healthier lives.
  • Learn the signs of overdose and have naloxone (Narcan, Kloxxado, RiVive) available. This is especially important if you know someone at risk of an opioid overdose or who struggles with an opioid use disorder (OUD). Narcan and RiVive are available to purchase from a local pharmacy without a prescription, while Kloxxado and other brand formulations of naloxone may require a prescription.
  • Take medication only as prescribed by your doctor. Don’t take medication that is not yours. If the medication is yours, take it exactly as prescribed. Tell your doctor about other medications and/or substances you are using.
  • Don’t combine drugs. Polysubstance use increases the risk of overdose. It’s never safe to combine drugs as the effects can be unpredictable.
  • Dispose of unused medication properly. The Food and Drug Administration provides detailed instructions for how and where to dispose of unused medicines.

Getting Help After an Overdose

If you or someone you care about experiences a drug overdose, it may be time to consider seeking professional treatment. Professional treatment can help you learn how to identify and modify harmful behaviors that may have contributed to drug use. While no single treatment is appropriate for everyone, you can expect an individualized treatment plan that includes a combination of:29

  • Behavioral counseling and therapy.
  • Medications.
  • Evaluation for and treatment of co-occurring mental health issues that commonly occur alongside addiction, such as anxiety, bipolar and depressive disorders.
  • Follow-up or continuing care focused on preventing relapse.

While not always necessary, professional detox can help you achieve a substance-free state as comfortably and safely as possible. This is an important component of treatment for many, as certain drugs (e.g., alcohol, benzodiazepines) can have potential complications and risks when abruptly reduced or stopped. For those with an opioid use disorder, there are medications that can be given during detox/withdrawal management that can significantly reduce and even eliminate certain withdrawal symptoms.30 Following detox with ongoing treatment in an inpatient or outpatient setting can help you achieve long-term recovery.29

If you or someone you care about may be struggling with addiction, American Addiction Centers (AAC) can help. AAC is a leading provider of evidence-based addiction treatment throughout the U.S. You can contact AAC 24 hours a day for information, resources, and support.

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