What Is A Lethal Dose Of Klonopin (Clonazepam)?

Medically Reviewed by Johnelle Smith, M.D. on August 1, 2023

Klonopin (clonazepam) is a prescription sedative. Mixing Klonopin with other depressants can lead to a fatal overdose. Treatment for Klonopin overdose may involve emergency medical care and a drug rehab program.

What Is The Lethal Dose Of Klonopin?

Klonopin (clonazepam) is a prescription sedative and central nervous system depressant. Taking an extremely high dose of Klonopin, or mixing it with other depressants can be fatal.

If someone has taken a lethal dose of Klonopin, call 911 or seek emergency medical attention right away. Klonopin is rarely fatal on its own, but can be deadly mixed with drugs.

Learn more about the lethal dose of commonly abused drugs.

How A Lethal Dose Of Klonopin Is Determined

Clonazepam is rarely associated with fatality when taken on its own.

Even instances of taking very high doses of Klonopin—more than 20 milligrams (mg), or 45 tablets—have resulted in patient recovery with prompt medical treatment.

The recommended daily dose of Klonopin is no more than 1.5 mg. In rats, lethal doses of Klonopin have been recorded at 4,000 mg/kg of weight.

Mixing Clonazepam And Opioids Can Be Fatal

While rarely fatal on its own, Klonopin can be deadly in combination with other depressants, including alcohol and opioids.

According to the National Institute on Drug Abuse (NIDA), almost 14 percent of opioid overdose deaths in 2021 involved benzodiazepines like Klonopin.

People who are prescribed both types of drugs should not take these drugs in any way other than the way prescribed by a doctor. This can lead to respiratory depression and death.

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Factors That Can Affect The Lethal Dose Of Klonopin

The lethal dose of Klonopin can vary according to a range of personal and biological factors.

Factors that can affect the lethal dosage include:

  • age
  • drug tolerance
  • use of multiple drugs
  • method of use
  • body composition
  • drug metabolism
  • liver function
  • kidney function

Taking Klonopin with other depressants is the number one predictor of serious Klonopin overdose. Together, multiple depressants can overwhelm the body much more quickly.

Recognizing The Signs Of A Klonopin Overdose

Overdose involving Klonopin or Klonopin with other drugs can be treatable with prompt medical attention. Knowing the signs of a drug overdose can be life-saving.

Signs and symptoms of Klonopin overdose include:

  • extreme drowsiness
  • very slow or shallow breathing
  • difficulty breathing
  • confusion
  • slurred speech
  • dilated pupils
  • very fast or slow pulse
  • impaired balance
  • loss of consciousness

If someone has collapsed, stopped breathing, or is unresponsive after taking a high dose of Klonopin, call 911 right away.

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This page does not provide medical advice. See more

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Medically Reviewed by
Johnelle Smith, M.D. on August 1, 2023

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