Written by: THE BALANCE
Medically reviewed by Dr. Sarah Boss, MD
Last updated: January 19, 2026
Fact checked
Quick Summary
  • Clonazepam is a psychoactive substance that acts as a central nervous system depressant by stimulating the release of GABA which is the principal inhibitory neurotransmitter in the brain.
  • It slows nerve conduction and causes relaxation and sedation thereby reducing the hyperexcitability of the brain as seen in several seizure disorders.
  • Since Clonazepam causes sedation it should not be used with other medications that induce drowsiness.

Clonazepam is a psychoactive substance that acts as a central nervous system depressant by stimulating the release of GABA which is the principal inhibitory neurotransmitter in the brain. It slows nerve conduction and causes relaxation and sedation thereby reducing the hyperexcitability of the brain as seen in several seizure disorders. Since Clonazepam causes sedation it should not be used with other medications that induce drowsiness. This includes a range of drugs that should not be taken with Clonazepam which are as follows:

  • Narcotic analgesics such as Morphine, Hydrocodone, and Oxycodone cause central nervous system depression, and the sedative effect of Clonazepam is exaggerated.
  • Anti-histamines such as Diphenhydramine (Benadryl) since this drug is known to cause sedation. 
  • Opioid medications such as cough syrups contain codeine that also exacerbates drowsiness.
  • Z-drugs such as Zolpidem (Ambien) which is a sleeping pill.
  • Other antipsychotics, anticonvulsants, and anxiolytics should not be used with Clonazepam since most of them work through the same mechanism of action and exert a depressive effect on the central nervous system. 

Simultaneously using any of these medicines with Clonazepam increases the risk of an overdose, the consequences of which can be fatal due to heightened depression of the respiratory centers in the brain. Therefore, you should always consult your doctors when you are taking any of these medications with Clonazepam to prevent the adverse effects that may result from such a combination. 

Clonazepam is an anticonvulsant, anxiolytic, and hypnotic. It is used to treat various seizure disorders, panic disorder, and anxiety following alcohol withdrawal. Clonazepam is a central nervous system depressant and so is alcohol therefore, you cannot mix Clonazepam and Alcohol since they both synergize the negative effects of each other which can lead to overdose, emergency room visits, and even death.  (source: MedlinePlus, n.d.-a)

Clonazepam Physical and Psychological Side Effects

Clonazepam (Klonopin) acts on the central nervous system through the GABA neurotransmitter and exerts a tranquilizing effect on the individual which helps them to function normally by controlling their seizure activity, or by reducing their anxiety. However, this calming effect can be addictive too and the individual often gets trapped in a cycle of abuse. Often, individuals develop a habit of poly-drug abuse in which more than one substance is used for abuse to develop a heightened euphoria and usually alcohol is used concomitantly with Klonopin to achieve the desired effect. Mixing Clonazepam and Alcohol can lead to increased danger; the greatest of which is developing an over sedation or having labored breathing due to the combined depressive effect of both drugs on the central nervous system which inevitably leads to coma in most cases. 

Clonazepam and Alcohol Mixing Side Effects

Side effects that result after mixing Clonazepam and Alcohol include the following: (source: NIDA, n.d.)

  • Drowsiness
  • Vomiting
  • Confusion
  • Slurred speech
  • Dizziness
  • Difficulty walking
  • Loss of coordination
  • Memory impairment
  • Unusual behavior
  • Poor decision-making ability 
  • Impaired judgment 
  • Slowed heart rate
  • Difficulty breathing
  • Liver damage
  • Increased risk of falls and injuries 
  • Coma

When individuals concomitantly use Clonazepam and alcohol they invite a plethora of adverse events to take place in their system. For instance, Alcohol and Clonazepam depress the respiratory centers in the brain which results in shallow breathing and impairs oxygen supply to vital organs such as the brain which ultimately leads to coma. It further causes a blue discoloration of lips and fingernails which highlights decreased oxygenation to peripheral body parts and this requires emergency medical treatment. 

It is rare to develop an overdose on Clonazepam when used as prescribed, however, when Clonazepam is misused and taken in large doses or for reasons other than the prescribed medical ones then an overdose is likely to develop. In addition, when Clonazepam is used with other central nervous system depressants such as alcohol, opioids, and medications listed above then the risk of developing an overdose increases by many folds.  (source: FDA, 2020)

Nicotine Withdrawal Symptoms and Luxury Treatment

However, not everyone who takes an increased amount of Clonazepam develops an overdose and certain factors influences the chances of developing an overdose. Firstly, the amount of Clonazepam consumed has a role in developing an overdose. Moreover, the metabolism and body chemistry of each individual varies and it has a great influence on the risk of developing an overdose since individuals who have a fast metabolism rapidly metabolize increased doses of the drug as compared to an individual who has a slow metabolism as seen in the elderly population. 

People should be aware of symptoms and side effects associated with Clonazepam overdose so that they can easily spot it when their loved ones are dealing with it and can provide them prompt medical treatment or else it can prove to be fatal.  (source: CDC, 2024)

Following are the symptoms and side effects of mild Clonazepam overdose:

  • Nausea
  • Lightheadedness
  • Blurred vision
  • Muscle weakness
  • Slow reflexes
  • Confusion
  • Agitation
  • Loss of balance
  • Impaired coordination 
  • Difficulty breathing 
  • Tremors 
  • Uncontrolled muscle movements 

Following are the symptoms and side effects associated with severe Clonazepam overdose: (source: NHS, 2023)

  • Low blood pressure
  • Respiratory depression
  • Slurred speech
  • Increased somnolence
  • Hallucinations
  • Extreme drowsiness
  • Abnormal heart rhythm 
  • Enlarged pupil
  • Weak and fast pulse 
  • Chest pain
  • Seizures
  • Loss of consciousness
  • Coma
  • Death 

Clonazepam is a highly effective benzodiazepine, with a relatively short onset of action and is used for the treatment of various seizure disorders. With Clonazepam’s ability to cause relaxation and sedation, there is significant room for the development of dependence on Clonazepam. Dependence on Clonazepam develops when the brain becomes used to the stimulating effect of Clonazepam and works effectively in its presence and once the drug’s supply ceases, the brain and body respond rather dramatically with the manifestation of unpleasant withdrawal symptoms that include physical, behavioral, and psychological component. 

The presentation of withdrawal symptoms is a hallmark of dependence on the drug and it is because the brain is adapting to function in the absence of the stimulus that is Clonazepam and produces a myriad of symptoms that are painful and perplexing for the individual to bear.  It is advised to not quit using Clonazepam abruptly as it can precipitate withdrawal episodes and one should taper the dose gradually under the direct supervision of a doctor since withdrawal from Clonazepam can be life-threatening. 

Several factors influence the severity of withdrawal symptoms such as the age of the individual since older individuals tend to experience intense withdrawal symptoms. Moreover, the amount of Clonazepam taken and the length of duration for which it is taken has a great say in the severity of withdrawal episodes as individuals taking increased doses for longer duration are likely to experience severe withdrawals symptoms.  (source: NIH/NLM, 2024)

In addition, co-occurring mental health disorders and personal history of addiction can heighten the withdrawal symptoms. Concomitantly abusing other substances with Clonazepam as seen in poly-substance abuse can also result in quite intense withdrawal symptoms. 

Clonazepam withdrawal presents myriad symptoms and side effects. (source: SAMHSA, 2020)

The physical withdrawal symptoms and side effects of Clonazepam withdrawal are as follows:

  • Stomach ache 
  • Nausea
  • Vomiting
  • Insomnia
  • Irregular heartbeat
  • Increased sweating
  • Loss of appetite
  • Increased blood pressure 
  • Blurred vision
  • Muscle spasm 
  • Tinnitus 
  • Extreme sensitivity to light 
  • Impaired motor functions
  • Lightheadedness 
  • Diarrhea 
  • Headache
  • Tremors
  • Dizziness
  • Fatigue
  • Confusion

Clonazepam withdrawal is associated with quite significant psychological symptoms, the most dangerous of which is the development of suicidal thoughts. Following are the several other psychological symptoms and side effects that result during Clonazepam withdrawal:

  • Depression
  • Anxiety
  • Seizures
  • Hallucinations
  • Nightmares
  • Suicidal thoughts
  • Mental confusion
  • Abrupt mood swings
  • Difficulty attaining pleasure
  • Irritability 
  • Trouble concentrating
  • Short-term memory loss
  • Panic attacks
  • Craving for Clonazepam
  • Feeling Agitated 
  • Lack of motivation
  • Anger issues

Clonazepam withdrawal duration is stretched over three phases. The first one is the early withdrawal phase, the second one is the acute withdrawal phase, and the third one is the protracted (late) withdrawal phase. However, not everyone goes through these three distinct phases of withdrawal since every individual has a different withdrawal timeline of Clonazepam depending upon how their body goes about in the absence of the drug.  (source: NICE, 2022)

The early withdrawal phase comprises the first 3 to 4 days after the last dose. During this early withdrawal phase, individuals experience rebound symptoms. These are the symptoms that were being treated under Clonazepam such as anxiety and insomnia that surface and result in rebound anxiety and insomnia however, these symptoms are short-lived and are due to the discontinuation of the drug which had suppressed them. 

The second phase of acute withdrawal lasts for 2 weeks to 3 months on average. It is during this phase that the withdrawal symptoms are at their peak. Acute withdrawal symptoms consist of a combination of somatic symptoms such as headache, sweating, and hand tremor accompanied by gastrointestinal symptoms such as nausea, vomiting, and stomach ache. During this acute phase, cardiovascular symptoms are quite prominent too with increased blood pressure and palpitations. During this stage, there is an increased risk of developing seizures and psychological symptoms. (source: WHO, 2014)

The third phase of protracted or late withdrawal begins after the symptoms of acute-phase have faded and it may last for months up to 2 years after cessation of Clonazepam. During this late phase, psychological symptoms dominate the picture. The individual feels generalized fatigue, cravings for the drug, anxiety, and depression. These symptoms fade gradually over months or a couple of years.

Clonazepam Overdose is a medical emergency and the medical staff will give activated charcoal to the affected individual on the way to the hospital to prevent the progression towards fatal consequences. After the individual is admitted to the hospital, his stomach is emptied to get rid of all the undigested Clonazepam to prevent future complications. Moreover, an antidote to benzodiazepine intoxication ‘flumazenil’ is given to reverse the toxic effects of Clonazepam overdose. 

To prevent future events of Clonazepam overdose, the individual should be enrolled for the treatment of Clonazepam addiction which involves multiple therapeutic techniques such as Cognitive Behavioral Therapy (CBT), individual and family counseling, and group support. Since Clonazepam addiction is a chronic condition it requires formal treatment in the form of rehabilitation. Rehabilitation is of two types an inpatient residential rehab treatment where facilities and supportive care are available round-the-clock. The second option is out-patient rehab treatment which suits people who prefer to live at home and receive treatment.  (source: StatPearls, 2025)

It is advised that to prevent Clonazepam withdrawal symptoms the drug should be tapered off slowly under the supervision of your doctor. It is best to not go cold turkey no matter how tempting it may feel to quit once and for all however, stopping Clonazepam abruptly gives rise to severe withdrawals symptoms that are hard to cope with. Clonazepam withdrawal is associated with the risk of seizures and hence several medications are used to ease the withdrawal process. These include:

  • Selective serotonin reuptake inhibitors which include Paxil and Prozac to mitigate the symptoms of Clonazepam overdose.
  • Certain anticonvulsant medications can also help to prevent the seizures such as Tegretol or Carbamazepine.
  • Melatonin, a hormone is used to treat insomnia which is frequently associated with withdrawal episodes of Clonazepam. 

These medications are part of the detox program that helps the individual get rid of all the traces of Clonazepam in the body with minimum symptoms. 

FAQs

How long do Clonazepam withdrawal symptoms last?
Clonazepam withdrawal symptoms vary in each individual. The symptoms may begin 3 to 4 days after the last dose and may continue for a couple of years in some people. However, in most people, the acute symptoms resolve within 3 months of the last dose.

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