Updated on April 3, 2024
6 min read

Morphine Overdose: How Much Morphine Can Cause Overdose?

Morphine affects the neurotransmitters and opioid receptors in the brain responsible for regulating dopamine levels. The active ingredient in morphine comes from the opium plant, a popular pain remedy.

Physical and psychological dependence are significant concerns with taking morphine. People frequently misuse or abuse it, often leading to addiction and overdose.

This article discusses morphine’s lethal dose, how to spot an overdose, and available treatment options for morphine addiction.

Can You Overdose on Morphine? 

Yes, it’s possible to overdose on morphine. Intentional or accidental overdoses can occur when taking this medication, especially if you take more than what your doctor prescribed.

Mixing morphine with other central nervous system (CNS) depressants can significantly increase the risk of overdose and death. You're also at risk of developing a tolerance the longer you take it.

Other risk factors that predispose you to overdose are: 

  • People with severe psychiatric and medical conditions such as depression, lung disease, HIV, and liver disease
  • Mixing morphine with other CNS depressants, such as alcohol, barbiturates, or benzodiazepines 
  • Misuse or use of the drug 
  • Taking more than the prescribed amount
  • Having an opioid use disorder
  • Injecting opioids
  • Resumption of morphine use after abstaining for a long time

How Much Morphine is Lethal?

It usually takes about 200 milligrams of morphine to cause a lethal overdose. However, there have been extreme cases where deadly drug overdose occurs with as little as 60 milligrams. 

A standard dose of morphine is between 20 to 30 milligrams. Moreover, most overdoses occur when users take the drug without a prescription.   

Overdose vs. Lethal Overdose

An overdose happens when you take more than the recommended or prescribed amount of a drug. It may lead to adverse effects and even death.

A lethal overdose means taking an amount of morphine that's fatal or deadly. The lethal dose varies, depending on body weight, age, tolerance levels, overall health status, and whether you’ve built up a dependency on it.

Opioids act on the CNS. Therefore, a morphine overdose can slow breathing and cause coma, respiratory failure, and death. 

Factors Influencing Morphine Overdose Risk

While you can overdose, the amount of morphine for this to occur depends on various factors, including your:

  • Specific condition
  • Underlying health issues
  • Tolerance level to the drug

Other major factors are depressant substances, such as alcohol and benzodiazepines, present in the bloodstream. Overdoses can happen even when taking morphine as prescribed, though this is much less common. 

What are Morphine Overdose Symptoms? 

Morphine overdose may be difficult to detect. Sometimes, it can make you look like you’re sleeping, but in reality, you’ve already overdosed on the substance. 

Recognizing overdose signs is imperative to know when to call for immediate assistance. These are the morphine overdose symptoms to look out for:

  • Loss of consciousness
  • A limp body that is unresponsive to outside stimulus
  • Slow, shallow, or erratic breathing
  • Stopped breathing
  • Faint or hard-to-detect pulse
  • Change in skin tone
  • Extremely pale or clammy face 
  • Choking or gurgling sounds 
  • Vomiting

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How to Prevent Opioid Overdoses

The best way to prevent opioid overdoses is not to take more than your body can tolerate. You should also address the root cause of opioid use and addiction. This includes:

  • Improving the opioid prescription process
  • Reducing exposure to opioids for everyone, especially youth
  • Preventing misuse through education
  • Treating opioid use disorder

When to Visit the Emergency Department (ED) 

If you or a loved one are experiencing the symptoms above, call 911 or seek urgent medical care immediately. If you suspect someone is overdosing, visiting the ED is necessary and can be life-saving. 

In 2021, opioids played a role in 80,411 overdose deaths, accounting for 75.4% of all drug overdose fatalities.

Centers for Disease Control and Prevention

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Treatment for an Opioid Overdose 

Treatment for an opioid overdose usually involves Naloxone. Healthcare professionals typically administer this, but you can carry a naloxone pen (nasal spray) for emergency use.

You must have proper training to use a Naloxone pen safely and effectively. You may also need resuscitation or CPR to treat someone who overdosed on opioids. Most cases require treatments that only doctors or trained healthcare professionals can administer. 

Treatment Options for Opioid Abuse & Addiction

Opioid use, misuse, and addiction have become a growing problem in the United States. Several options are available for opioid use disorder, including:

Medication-Assisted Therapy (MAT)

Medication-assisted therapy (MAT) is most effective with other treatments. It involves Buprenorphine, Methadone, and Naltrexone for opioid use disorder.

Buprenorphine and methadone help manage withdrawal symptoms as you detox. Naltrexone blocks the receptors that opioids bind to, making it impossible to get high.

Inpatient Programs 

Inpatient programs are the most intensive addiction treatment options. These programs guide you through:

  • Medically supervised detoxification
  • Behavioral therapy
  • Other services like medication-assisted therapy

They typically last 30, 60, or 90 days. However, they may be longer if necessary.

Partial Hospitalization Programs (PHPs)

Intensive outpatient programs are the next level of addiction treatment. These programs provide similar services to inpatient programs, such as detoxification and behavioral therapy.

The difference is that you return home to sleep. Some programs also include transportation and meals. PHPs are ideal for new patients and those who have completed inpatient treatment but still need intensive care.

Outpatient Programs

Outpatient programs provide well-rounded treatment for people with a high motivation to recover. These programs are flexible and customizable to work around your schedule. They work for new patients and those who have completed inpatient or partial hospitalization programs.

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Why is Morphine Dangerous?

Morphine use is dangerous because it's highly addictive. It’s one of the strongest opioid analgesics and central nervous system (CNS) depressants.

Morphine is for moderate to severe acute and chronic pain relief and management. You can inject or take it orally, although only healthcare professionals can legally administer it.

Using cheaper alternatives in larger quantities increases the risk of overdosing. Doing so also raises the likelihood of developing physical dependence.

What are the Side Effects of Morphine? 

Aside from the risk of overdose, there are other potential side effects of morphine use. You can develop an addiction or physical dependency on the drug. 

As a prescription, it causes mild side effects. However, you can develop dangerous and life-threatening side effects when you misuse it.

These side effects include:

  • Nausea 
  • Vomiting
  • Constipation
  • Loss of appetite
  • Lower blood pressure (hypotension)
  • Lowered body temperature (hypothermia)
  • Difficulty urinating
  • Drowsiness 
  • Dizziness 
  • Confusion
  • Nervousness
  • Weakness
  • Sleepiness or sedation
  • Inability to concentrate 
  • Changes in heart rate 
  • Respiratory depression 
  • Dry mouth
  • Feelings of calmness, euphoria, or a false sense of well-being 

Severe Side Effects

Long-term use or abuse can lead to more serious adverse effects, including:

  • Increased blood sugar levels 
  • Chronic stomach pain
  • Bloating and stomach acid reflux
  • Severe weight loss 
  • Decreased sexual drive and sexual dysfunction
  • Immune system disturbances
  • Chest pain 
  • Hallucinations 


A morphine overdose is a potentially life-threatening situation. It can occur due to various factors, such as underlying health issues and tolerance level to the drug.

Recognizing overdose symptoms is crucial in seeking immediate medical attention. The most common treatment for an opioid overdose involves the use of Naloxone, but long-term treatment options are also available for opioid use disorder.

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Updated on April 3, 2024
13 sources cited
Updated on April 3, 2024
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  3. Ben-Saghroune et al. “Assessment of the Safety and Efficiency of a Preperitoneal Continuous Infusion Using Bupivacaine after Abdominal Laparotomy in Digestive Carcinology.” Anesthesiology Research and Practice, 2023.
  4. Gálvez et al. "Is morphine still the best reference opioid?" Pain Management, 2012.
  5. Brown et al. Effectiveness and safety of morphine sulfate extended-release capsules in patients with chronic, moderate-to-severe pain in a primary care setting." Journal of Pain Research, 2012.
  6. "Drug Overdose Death Rates." National Institute on Drug Abuse, 2023.
  7. Listos et al. “The Mechanisms Involved in Morphine Addiction: An Overview.” International Journal of Molecular Sciences, 2019. 
  8. Boorman et al. “Sex differences in morphine sensitivity are associated with differential glial expression in the brainstem of rats with neuropathic pain.” Journal of Neuroscience Research, 2022.
  9. Morphine.” Bethesda (MD): National Institute of Diabetes and Digestive and Kidney Diseases, 2020. 
  10. Marghmaleki et al. “Physical Activity on Symptoms of Morphine Addiction in Rats, after and before of Lesion of the mPFC Area.” Iranian Journal of Basic Medical Sciences, 2013.
  11. Gálvez et al. “Is morphine still the best reference opioid?” Pain Management, 2012.
  12. Rach, M. “A brief history of morphine use.” Mayo Clinic, 2023.
  13. Drug Overdose Deaths.” Centers for Disease Control and Prevention, 2023.

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