Yes, it is possible to overdose on Klonopin (clonazepam), which is why you should always take your medication as prescribed.
A Klonopin overdose can include the following signs and symptoms:[1,2]
Slurred speech
Ataxia (impaired coordination, such as what is associated with intoxication)
Altered mental status
Drowsiness
Double vision
Clammy skin
Bluish tint around the lips and fingertips
Shallow or stopped breathing
Slowed or stopped heartbeat
Severe confusion
Trouble responding
Pulmonary aspiration
Unconsciousness or coma
Are you or someone you know struggling with addiction?
I may have a problem I am concerned for a loved oneHowever, a life-threatening overdose is rare if a person has only been taking a benzodiazepine like Klonopin. It is much more common if they were instead mixing benzodiazepines with other depressant drugs like alcohol or opioids.[1],[2]
Clonazepam and various other benzodiazepines are Schedule IV controlled substances, meaning they are generally considered safe when used as prescribed, but they do carry some potential for abuse, dependence, and addiction. If someone takes too much Klonopin, especially if they mix it with certain other drugs, there is a potential for an overdose and life-threatening consequences.
Klonopin Overdose Symptoms
A Klonopin overdose will commonly be characterized by the following signs and symptoms:[1,2]
Slurred speech
Ataxia (impaired coordination, such as what is associated with intoxication)
Altered mental status
Drowsiness
Double vision
More serious is the fact benzodiazepines can cause respiratory depression. When taken alone, even in excess, this usually won’t be severe enough to be a major concern, although it can still be an issue if taken in extreme doses or if a person suffers from certain health conditions. The risk becomes more significant if the drugs are mixed with other substances that can cause respiratory depression, such as alcohol, opioids, or barbiturates.[2]
Signs of potentially life-threatening respiratory depression include the following:[1,2]
Clammy skin
Bluing around the lips and fingertips
Shallow or stopped breathing
Slowed or stopped heartbeat
Severe confusion
Difficulty or inability to respond
Pulmonary aspiration
Unconsciousness or coma that a person struggles to awaken from
A person experiencing any of the symptoms above, including those not associated with respiratory depression, should be considered to be having a medical emergency.
Complications of Benzodiazepine Overdose
Some complications associated with benzodiazepine overdose or Klonopin toxicity include:[2]
Aspiration pneumonitis (from inhaling stomach contents into the lungs)
Rhabdomyolysis, or the breakdown of muscle tissue, which can cause kidney damage
Respiratory arrest
Death
Factors That Increase the Risk of Klonopin Overdose
Some factors that increase the risk of experiencing a Klonopin overdose include the following:
Using Opioids at the Same Time
Benzodiazepines like Klonopin are central nervous system depressants. Opioids are depressants too. Combining them could lead to higher overdose risks.
In a study of more than 2 million patients, researchers found that people exposed to both benzodiazepines and opioids had higher overdose risks than people who took just opioids.[7]
Continued Access to Drugs
It’s easier to overdose when you have plenty of drugs to work with. In 2023, researchers examined people with Medicare prescription drug coverage and a benzodiazepine prescription between April 2016 and December 2017. They found that people more likely to overdose had more drugs dispensed by their doctors.[8]
Shopping for Doctors
People who visit multiple doctors and ask for prescriptions are more likely to overdose than people who see the same doctor all the time. In a study of 529,053 people with insurance, researchers found that overdose risk was increased 1.8-fold when people had prescriptions from multiple prescribers.[9]
Using the Drug in an Unusual Manner
Some people crush their Klonopin pills and inhale them. Others crush their pills, mix the powder with water, and inject the solution. These methods are incredibly dangerous, as they put all the power of the drug into the body in seconds instead of allowing it to move into the body slowly through the digestive system.
Your Metabolism
Some people are at risk of overdose while taking doses of Klonopin that are safe for other people. If you’re very small or underweight, you may not be able to take high doses of benzodiazepines, as they could flood the system.
Organ Health
Benzodiazepines like Klonopin are metabolized by the liver.[10] If yours isn’t healthy, your dose could build up within your body and cause an overdose. Your liver disease might be caused by age or another disease.
How Much Klonopin Does It Take to Overdose?
It’s rare for a person to overdose on Klonopin on its own because benzodiazepines have a high therapeutic index, which means the difference between the therapeutic dose and the toxic dose is large.
However, experts consider the toxic dose of Klonopin to be above 0.08 mcg/mL of blood in the body.[2] The amount of blood in the adult human body ranges based on size and weight, so it’s difficult to determine how much a pill would raise an individual’s blood concentration. However, the maximum dose for Klonopin for panic disorder is 4 mg in one day, and it’s 20 mg for seizure disorder.
Again, with Klonopin, there’s a big gap between the effective dose and a toxic dose. You’d need to take a much larger dose than prescribed to experience serious side effects.
Taking more likely won’t be fatal, but it’s never a good idea to take more Klonopin than prescribed. You should always follow your doctor’s directions carefully to avoid side effects, overdose, and other harmful consequences.
What to Do in the Event of an Overdose: Step by Step
If you believe you or someone around you is experiencing an overdose related to Klonopin or other benzodiazepine use, call 911 immediately. If possible, have the following information ready:
Your location
The affected individual’s current status, including any physical and mental symptoms they’re experiencing
The affected individual’s medical history
Any substances the overdosing individual has taken recently, including both prescription medication and any illicit or recreational drugs
If a person is experiencing severe respiratory depression to the point where they cannot get enough air to support their brain, begin CPR.
If they have used opioids in combination with Klonopin, administer naloxone (Narcan) if any is available, as this drug can rapidly reverse an opioid overdose.
How Are Klonopin Overdoses Treated?
In the hospital, Klonopin overdoses are treated mainly with medical observation and supportive care, including these methods:[1,2]
Airway support
If people aren’t breathing independently, doctors can place an endotracheal tube to keep the airway open and deliver oxygen.
Hydration
Fluids delivered by a needle can help to replace the liquid lost by high body temperatures and sweating. Fluid therapy can also help to protect organs from damage.
Monitoring vital signs
Doctors ensure their patients are improving by checking their blood pressure and temperature regularly. If patients get worse, doctors can shift their treatment approach accordingly.
Medications
People who aren’t breathing at a normal rate may benefit from atropine.
The medical team may administer flumazenil, which is an antagonist at the benzodiazepine receptor site, to reverse the effects of Klonopin overdose. However, this should be used with caution because flumazenil lowers the seizure threshold and increases the risk of cardiac dysrhythmias. Often, the risks outweigh the benefits of this medication, so it isn’t typically used. It can also cause dangerous withdrawal symptoms in people who are dependent on or addicted to Klonopin.[1,2]
How Long Does Klonopin Stay in Your System?
- Benzodiazepine Toxicity. (June 2022). StatPearls.
- Clonazepam. [Updated 2023 May 13]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing.
- Benzodiazepine Use and Misuse Among Adults in the United States. (February 2019). Psychiatric Services.
- Clonazepam (Klonopin). (September 2021). National Alliance on Mental Illness.
- Sleeping Pills and Minor Tranquillisers. (April 2021). Mind.
- Flumazenil in Benzodiazepine Overdose. (December 2016). Canadian Medical Association Journal.
- Risk of Overdose with Exposure to Prescription Opioids, Benzodiazepines, and Nonbenzodiazepine Sedative-Hypnotics in Adults. (January 2020). Journal of General Internal Medicine.
- Prescription Characteristics Associated with Drug Overdose Risk Among Adults Prescribed Benzodiazepines. (May 2023). BMC Pharmacology and Toxicology.
- Association Between Receipt of Overlapping Opioid and Benzodiazepine Prescriptions from Multiple Prescribers and Overdose Risk. (August 2021). JAMA Network Open.
- Lorazepam. (June 2022). LiverTox.