Call Our 24/7 Addiction Hotline 800-891-9360 Who Answers?

What Is a Lethal Dose of Methadone?

While methadone has helped millions of people with overcoming addiction and dealing with chronic pain, that doesn’t mean it comes without risk.

When taken at a doctor-recommended dose, most people tolerate methadone just fine. However, for those who try to abuse methadone, there can be deadly consequences.

Because methadone is an opioid, it poses many of the same overdose risks as other similar drugs, such as heroin or oxycodone.

Knowing what that lethal dose of methadone is can save your life if you’re at risk for abusing it.

If you think you’re going to abuse your methadone, the best thing to do is give us a call at 800-891-9360(Who Answers?).

We can help you get the treatment you need to help you get off drugs once and for all.

What Is Meant by a Lethal Dose of Methadone?

Lethal Dose

Low blood pressure and drowsiness are warning signs of a methadone overdose.

Simply put, there is no single level of methadone which is guaranteed to be toxic.

What’s toxic for one person might not even have any effects on another.

This is because some people have built-up tolerance to methadone. For example, if you’ve previously taken opioid drugs, you probably have a rather high tolerance to methadone.

This is because opioid drugs work by stimulating the opioid receptors in the brain. Over time, your brain begins to adjust to this constant stimulation by requiring more and more opioids to achieve the same stimulating effects.

Because of this, a person who takes opioids on a regular basis would be able to withstand a much higher dose of methadone than a person who has never taken opioids before in their life.

In fact, studies show that most people who die from methadone overdose have blood concentrations of the drug that are so low they wouldn’t have any effect on a person undergoing regular methadone maintenance therapy.

Understanding the Standard Methadone Dose

Methadone comes in three different dosing sizes5mg, 10mg, and 40mg. For people suffering from acute pain, doctors typically prescribe the 5mg or 10mg dose, as most of these people will not have any methadone tolerance and would not be able to withstand a higher dose.

In fact, some studies have shown that the minimum toxic dose in a normal adult who has not had previous opioid tolerance could be as low as 30mg to 50mg.

In children, this minimum lethal dose could be as low as 10mg.

For opioid-addicted people, these levels are much higher. In fact, they might take doses of over 100mg each day without any discernible side effects.

Combining Methadone with Other Medications

Another way that it’s possible to create a lethal dose of methadone is if you mix it with other medications.

For example, mixing methadone with benzodiazepines can lead to cardiotoxicity and cause deadly side effects.

Additionally, if you continue to abuse other drugs, such as other opioids, alcohol, or cocaine, you could suffer serious respiratory depression or abnormal heart rhythms that could cause death.

What to Know about Methadone Overdose Treatment

Symptoms of a Methadone Overdose

There are certain signs and symptoms you will begin to experience if you’ve taken too much methadone. It’s important to look out for these and seek medical attention right away if you notice them. The most common overdose symptoms include:

  • Weak pulse
  • Low blood pressure
  • Constricted pupils
  • Vomiting or nausea
  • Stomach pain and constipation
  • Trouble breathing or cessation of breathing
  • Extreme tiredness
  • Dizziness and drowsiness
  • Coma and cold skin

You may or may not notice symptoms right away, as methadone does take some time to disperse through the body.

Because a lethal dose of methadone varies between people, it’s important to always talk with your doctor before starting on methadone.

If you need help finding a methadone doctor in your area, we can help. Simply call us now at 800-891-9360(Who Answers?).

Where do calls go?

Calls to numbers on a specific treatment center listing will be routed to that treatment center. Additional calls will also be forwarded and returned by one of our treatment partners below.

Calls to any general helpline (non-facility specific 1-8XX numbers) for your visit will be answered by ARK Behavioral Health, a paid advertiser on

All calls are private and confidential.

Who Answers?