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Klonopin side effects and how to avoid them

Klonopin treats certain types of seizures, and can treat panic attacks associated with panic disorder. Learn about the side effects of Klonopin, as well as potential drug interactions and the risks of misuse.

Klonopin side effects | Serious side effects | Impairment |
Suicide | How long do side effects last? | Warnings | Interactions | How to avoid side effects | Resources

Klonopin is a brand-name prescription drug that is used to manage certain types of seizures in adults and children. It is also used to treat panic attacks in adults diagnosed with panic disorder. The active ingredient in Klonopin is clonazepam, a benzodiazepine that quiets brain activity by increasing the effects of a neurotransmitter called GABA. As an inhibitory molecule, GABA slows down nerve activity in the brain. 

While it can be effective as an anticonvulsant and anti-anxiety drug, Klonopin can cause side effects. To prevent problems when taking Klonopin, it helps to know the side effects of taking the medication as well as potential drug interactions and the risks of misuse and dependence.

RELATED: What is Klonopin? 

Common side effects of Klonopin

Most people taking Klonopin will experience some side effects, usually drowsiness or other impairments. The most common side effects of Klonopin are:

  • Drowsiness
  • Loss of coordination
  • Dizziness
  • Fatigue
  • Depression
  • Memory problems
  • Impaired intellectual function
  • Slurred speech
  • Constipation
  • Painful menstrual cramps
  • Loss of appetite
  • Blurred vision
  • Erectile dysfunction
  • Decreased libido
  • Confusion
  • Sore throat
  • Elevated liver enzymes
  • Skin rash

Serious side effects of Klonopin

Serious side effects of Klonopin include: 

  • Suicidal thoughts or behaviors
  • Trouble breathing, or respiratory depression, especially when taken with opioids
  • Abuse and dependency
  • Withdrawal reactions, including protracted withdrawal syndrome 
  • Worsening of seizures in people with seizure disorders
  • Paradoxical reactions such as irritability, anxiety, agitation, and psychosis

Klonopin and mental impairment

Clonazepam acts as a sedative and anti-anxiety medication by slowing down brain activity. As a result, mental, motor, and mood changes are common side effects, including sleepiness (50% incidence), poor motor coordination (30% incidence), and unexplained behavioral changes (20% incidence). As a result, Klonopin can make people more vulnerable to falls, injuries, and accidents. If impairment is a problem, a healthcare provider may caution against driving or engaging in risky activities with machinery. Safety measures may need to be made in the home to prevent falls and accidents. Other substances that also cause impairment, like alcohol or sleeping pills, should be avoided while taking Klonopin. 

Klonopin and suicide

A small number of people taking clonazepam may experience a worsening of depression and suicidal thoughts or behaviors. In the initial clinical trials evaluating the safety and effectiveness of Klonopin, 0.43% of patients taking Klonopin showed signs of suicidality. Suicidal thoughts and behaviors may be serious enough that patients and caregivers should watch for any changes in mood, feelings, thoughts, and behaviors and seek immediate medical advice if these changes occur. Healthcare providers are trained to identify signs of suicide, so make sure to keep all follow-up appointments.

How long do side effects last?

Most of the side effects of clonazepam are often associated with the drug’s sedative effects. These effects are usually temporary and may wear off about a day or two after the last dose. However, depending on how long the duration of treatment with Klonopin was before stopping the medication, withdrawal effects could start one to three days after the last dose and last for weeks to months. 

The most serious side effects of Klonopin are suicidal thoughts or behaviors, respiratory depression, seizures, and coma, which can often occur as a result of abuse, misuse, and physical dependence on the drug.

  • Respiratory depression, seizures, and coma typically require emergency medical attention. 
  • Suicidal thoughts or behaviors should improve after the drug is discontinued. 
  • Physical dependence is managed by tapering, or gradually lowering the dose of the drug, over several weeks. 
  • Withdrawal is a longer-term problem that could take weeks or months to resolve. 
  • Drug abuse is a chronic problem that may require months, years, or a lifetime to manage.

Klonopin contraindications & warnings

Healthcare professionals may consider several factors before prescribing a benzodiazepine like Klonopin. There are certain precautions to consider before taking Klonopin as this drug may not be appropriate for everyone.

Abuse and dependence

Clonazepam is a Schedule IV drug that carries a potential for drug abuse. The body can develop a physical dependence on clonazepam as well as a tolerance to the effects of clonazepam after long-term use. Physical dependence and tolerance could lead to withdrawal symptoms after discontinuing the use of the medication. Drug abuse, physical dependence, tolerance, and withdrawal are included in the black box warning on the U.S. Food and Drug Administration (FDA) label. 

Physical dependence and tolerance can lead to drug abuse, which could encompass exceeding prescribed doses, acquiring multiple unnecessary prescriptions, and purchasing the drug illegally. About 1%–2% of people in the U.S. misuse or have misused a benzodiazepine. Because the body can build a tolerance to benzodiazepines, people abusing Klonopin may have to take ever-increasing doses to achieve the same effects over time. Chronic and excessive Klonopin use can raise the risk of serious side effects, hazardous drug interactions, and a potentially life-threatening overdose.

In prescription doses, clonazepam can be taken safely for two to four weeks. After that, stopping clonazepam may lead to withdrawal symptoms. These symptoms can be mild to severe and typically last for a couple weeks, in mild cases, to several months, in severe cases. To prevent withdrawal, a healthcare provider will usually prescribe a tapering dose over a few days or weeks, although some withdrawal symptoms may still be experienced. About 15–44% of patients who have taken a benzodiazepine for three to six weeks may experience protracted withdrawal symptoms upon discontinuing the drug. Protracted withdrawal can last anywhere from a few months to more than 12 months after the benzodiazepine has been discontinued.


Get emergency medical treatment if symptoms of overdose are apparent, such as somnolence, confusion, slowed reflexes, muscle weakness, and coma. 


Not everyone can take Klonopin, especially those with certain underlying medical conditions. Some people are never given Klonopin because of pre-existing conditions. These include people who are allergic to benzodiazepines, such as Valium (diazepam), Xanax (alprazolam), and Ativan (lorazepam). Klonopin is not recommended for people with severe liver disease or acute narrow-angle glaucoma.

Klonopin should be used under the supervision of a healthcare provider, especially in people with certain conditions and medical histories.

  • Because clonazepam is easily abused, people with a history of substance abuse disorders may be evaluated to determine if treatment with clonazepam is appropriate. 
  • Healthcare providers may monitor the use of Klonopin in those with depression, as Klonopin may increase the risk of worsening depression.
  • Klonopin, an anticonvulsant, may make seizures worse in some people with complex seizure disorders. Healthcare providers may add one or two more anticonvulsants to the treatment regimen for treating seizures.
  • Because Klonopin can cause breathing problems, patients with lung problems, such as sleep apnea, should use Klonopin with caution.
  • People with kidney disease may need regular blood tests to make sure clonazepam by-products aren’t building up in the bloodstream.
  • People with porphyria may need to be monitored to make sure Klonopin isn’t worsening the condition.

Pregnancy and nursing

There are no studies that identify the risks of Klonopin to the human fetus, and experience with clonazepam in pregnant women is inconclusive. Still, Klonopin may cause harm to an unborn baby and is not generally recommended to pregnant women. It is important that women inform the prescribing healthcare provider about any pregnancy. When clonazepam is taken in the last trimester, newborns may be more likely to experience withdrawal symptoms, problems with feeding, or difficulty breathing.

Klonopin can pass into breast milk, which may warrant the use of caution when prescribing clonazepam during breastfeeding. Breastfed infants whose mothers take clonazepam may experience sedation. It is important for a mother on Klonopin to consult with a healthcare provider to determine an appropriate method for feeding an infant.


The FDA has approved Klonopin for the treatment of seizure disorders in children. Some healthcare providers will, however, prescribe Klonopin off-label for anxiety disorders or other conditions in children and teens, but the safety and effectiveness of Klonopin treatment for these conditions have not been established in those under the age of 18. If Klonopin is prescribed, a healthcare provider may determine an appropriate dose based on the child’s weight. A provider may also recommend monitoring for possible adverse effects, such as mood and behavioral changes, as well as problems with mental and physical growth.


The normal dosing range of Klonopin is the same in older adults as younger adults. However, the starting dose may be lower. Healthcare providers may closely monitor older patients for adverse effects.

Klonopin interactions

As with all prescription drugs, Klonopin can cause problems when taken with other prescription or over-the-counter drugs. In general, the most serious drug interactions either cause excessive sedation or seizures. Excessive sedation can lead to a number of potentially serious problems, such as shallow breathing, mental impairment, fainting, falls, accidents, and injuries. Severe sedation is often associated with overdose, which can also lead to respiratory depression, coma, and death.

Drugs that lower seizure threshold

Klonopin is used as an anticonvulsant, or a drug used to manage seizures. However, certain drugs can lower the seizure threshold, making seizures more likely when taken with Klonopin. The use of some of these drugs may need to be avoided or monitored while taking Klonopin. 

  • Wellbutrin (bupropion)
  • Ludiomil (maprotiline)
  • Firdapse (amifampridine)
  • Ampyra (dalfampridine) 
  • Reglan (metoclopramide)

Certain drugs like theophylline and antibiotics, such as levofloxacin and ciprofloxacin, can lower the seizure threshold. The use of these drugs with Klonopin may need to be monitored.

Drug interactions that cause excessive sedation

Many different types of drugs slow down the brain. These drugs are called central nervous system depressants, or CNS depressants. The FDA has placed a black-box warning on Klonopin recommending that opioids be avoided because of the risk for respiratory depression, coma, and death. CNS depressants that should be avoided or monitored in combination with Klonopin include:

Other drugs can slow down the brain and worsen the sedative effects of Klonopin. They should also be avoided or used cautiously. These include 

How to avoid Klonopin side effects

As with other drugs, side effects are possible when taking Klonopin. Still, there are ways to minimize the risk and severity of Klonopin’s side effects

1. Take Klonopin as directed

Take this medication as directed by a healthcare provider. The dose may change several times during treatment. Doses may have to be taken on a schedule. 

2. Read the medication guide

The Klonopin medication guide has valuable information about identifying and avoiding side effects as well as instructions on how to take the medication safely. Read this medication guide thoroughly. If you have any questions, talk to a pharmacist or healthcare provider. 

3. Tell the doctor about all medical conditions

Many side effects are due to underlying medical conditions. When a healthcare provider prescribes Klonopin, they need to know about all existing medical conditions, especially:

  • Liver or kidney problems
  • Lung problems or respiratory disease
  • Depression, mood problems, or suicidal thoughts or behaviors
  • Porphyria
  • A history of allergic reactions to benzodiazepines
  • Pregnancy or pregnancy plans
  • Breastfeeding or any plans to breastfeed

4. Do not stop taking Klonopin

Stopping Klonopin abruptly can cause withdrawal. Always go to a healthcare provider if Klonopin is causing problems or not working. The safest way to stop Klonopin is to use a steadily decreasing dose as instructed by a healthcare provider.

5. Report any changes or problems to a healthcare provider

It’s very important to talk to a healthcare provider when there are problems while taking this medication. Mood changes, behavior changes, anxiety, impulsiveness, trouble sleeping, or other mental health issues should be reported before they become serious problems. Side effects and any worsening of symptoms, such as seizures, should be immediately reported to the prescribing healthcare provider. Seek immediate medical attention in the event of an overdose, which may lead to trouble breathing, coma, or death.

6. Be careful while driving and other risky activities

Klonopin can cause drowsiness and dizziness, and it can also affect your motor skills and coordination. Driving, operating machinery, or engaging in risky activities that require attention, focus, and coordination could be hazardous. It’s a good idea to avoid these activities until the effects of the drug are well-understood or treatment has stopped.

7. Avoid drinking

Drinking and Klonopin don’t mix. They are both CNS depressants and powerful sedatives. Combining the two can cause drowsiness, coordination problems, and trouble breathing. Severe drowsiness and impaired motor skills substantially raise the risk of falls, injuries, and accidents.