By Naomi Carr

Last updated: 13 February 2024 & medically reviewed by Morgan Blair

Klonopin (clonazepam) is a benzodiazepine, used to treat several physical and mental health conditions, including seizures and panic disorder. Klonopin (clonazepam) can cause many side effects, including drowsiness, dizziness, unsteadiness, and cognitive impairments. It can also cause severe side effects, particularly if it is abused or used for a prolonged period.

Klonopin (Clonazepam) Side Effects

What is Klonopin?

Klonopin is a brand name for the benzodiazepine medication clonazepam. It is approved for use as a short-term treatment for various conditions. It is also regularly misused and abused, causing it to be classified as a Schedule IV controlled substance.[1][2] 

What is Klonopin used for?

Klonopin (clonazepam) is approved to treat panic disorder and seizure disorders. It is also sometimes used to treat other anxiety disorders, sleep problems, and alcohol withdrawal. It is not intended for long-term use, due to its risk of abuse and addiction.[1][3]

The effects of Klonopin (clonazepam) can be felt within an hour of administration, making it an effective medication for acute anxiety symptoms. It is also a sedative and muscle relaxant, thereby making it effective for movement, seizure, and sleep conditions.[3][4]

Why do people abuse Klonopin?

Klonopin (clonazepam) is regularly abused and used for unintended purposes. It works quickly and causes mild euphoria, with a sedating and calming effect. Because of these effects, it is used recreationally or for unintended purposes. Additionally, benzodiazepines such as Klonopin (clonazepam) are commonly used alongside opioids to enhance euphoric effects.[2]

Klonopin (clonazepam) is habit-forming and highly addictive when abused or used for more than several weeks, which contributes to its likelihood of abuse.[1] 

If Klonopin (clonazepam) is prescribed for a brief treatment and then stopped, the symptoms being treated may be likely to persist. For example, someone might be prescribed Klonopin (clonazepam) to manage acute anxiety symptoms. If this prescription is stopped, they might feel unable to manage their symptoms without the medication and attempt to get the drug illegally.[5]

Similarly, someone who has been prescribed Klonopin (clonazepam) for a prolonged period might develop a physical dependence on the medication. This can cause withdrawal symptoms when the medication is stopped, potentially causing individuals to seek illegally obtained Klonopin (clonazepam) to prevent unpleasant effects.[1][2]

Common side effects of Klonopin

When starting a new medication, it is common to experience side effects. Often, these side effects will reduce within one to two weeks without the need for professional intervention.[4] If any of these side effects persist or become concerning, it is advised to contact the prescribing doctor.

Common side effects of Klonopin (clonazepam) include:[1][3][4][6]

  • Drowsiness

  • Dizziness

  • Muscle weakness

  • Pain in the muscles or joints

  • Unsteadiness

  • Depression

  • Memory or concentration issues

  • Blurred vision

  • Sexual dysfunction, such as decreased libido

  • Increased saliva

  • Increased urination

  • Vivid dreams

Severe side effects of Klonopin

In some cases, Klonopin (clonazepam) treatment can cause severe side effects. The risk of this is increased if the medication is misused or abused. If severe side effects occur, consult a medical professional immediately. 

Severe side effects of Klonopin (clonazepam) include:[3][4][6]

  • Suicidal thoughts

  • Severe mood changes

  • Severe depression or anxiety symptoms

  • Aggression or violence

  • Panic attacks

  • Agitation or restlessness

  • Hallucinations

  • Psychosis

  • Breathing difficulties

  • Rash or hives

  • Difficult swallowing

  • Yellowing of the skin

  • Severe loss of coordination or limb control

  • Unexplained bruising or bleeding

  • Swelling of the mouth, face, or throat

  • Fainting

  • Slurred speech or difficulty speaking

  • Rapid heart rate

  • Sleepwalking or doing activities while not fully awake

Severe side effects are more likely in individuals who abuse Klonopin (clonazepam). This includes an increased risk of heart issues, breathing difficulties, extreme weakness and fatigue, severe mood changes, and loss of consciousness.[1][2] 

Klonopin (clonazepam) abuse also increases the risk of dependence and addiction developing.[1] 

Klonopin (clonazepam) dependence occurs with prolonged use and causes the individual to become reliant on the effects of the medication. When the medication is stopped, withdrawal symptoms occur, such as anxiety, seizures, nausea, insomnia, and irregular heartbeat. This contributes to the continued use of the medication as an attempt to prevent Klonopin withdrawal symptoms.[6]

Addiction often occurs alongside physical and psychological dependence. It can cause compulsive drug-seeking behaviors and can have detrimental effects on the individual’s quality of life and well-being.[5]

Klonopin (clonazepam) can cause severe breathing difficulties or extreme sedation if it is used alongside other central nervous system depressants such as opioids or alcohol. In some cases, these effects can be fatal.[1][7]

Klonopin overdose

Klonopin (clonazepam) is a central nervous system depressant and causes effects such as reduced heart rate and sedation.[3] As such, abusing Klonopin (clonazepam) can increase the risk of overdose and potentially fatal effects.

Signs of a Klonopin (clonazepam) overdose include:[1][6]

  • Extreme weakness and tiredness

  • Confusion

  • Slowed movement

  • Breathing difficulties

  • Unresponsiveness

Klonopin (clonazepam) overdose often occurs when the medication is used with another drug, such as an opioid. Overdose is also common in individuals who relapse after being treated for substance use disorders. This often occurs because the individual has not used the drug for some time and takes a higher dose than their body can tolerate.[3][7]

Getting treatment

When an individual begins Klonopin (clonazepam) treatment, the doctor will gradually increase the medication to prevent severe side effects. Similarly, after treatment, they will gradually taper the prescription before stopping the medication to prevent withdrawal symptoms.[1]

If someone abuses Klonopin (clonazepam) or has developed a physical dependence or addiction to the drug, they may require a medical detox to safely reduce and stop their substance use. This can be provided in a hospital or inpatient rehabilitation facility, where professionals can monitor and manage any withdrawal symptoms and dangerous effects that occur.[5]

Treatment provided to help with this process can include:[8][9]

  • Psychotherapy: Various therapies, including cognitive behavioral therapy (CBT), can help to reduce addictive behaviors, manage mental health symptoms such as anxiety and depression, and provide coping skills to manage triggers and cravings. 

  • Medications: Withdrawal symptoms can be managed with medications such as antidepressants, anticonvulsants, or beta-blockers.

Following treatment for a substance use disorder, such as Klonopin (clonazepam) addiction, many individuals benefit from ongoing treatment. This can include psychotherapy, support groups, 12-step programs, and holistic therapies. These interventions can improve the recovery process and help to maintain abstinence.[9]