Generic name: clonazepam (kloe NA ze pam)
- Tablets: 0.5 mg, 1 mg, 2 mg
- Orally disintegrating tablets: 0.125 mg, 0.25 mg, 0.5 mg, 1 mg, 2 mg
Brand name: Klonopin®
- Tablets: 0.5 mg, 1 mg, 2 mg
All FDA black box warnings are at the end of this fact sheet. Please review before taking this medication.
What Is Clonazepam And What Does It Treat?
Clonazepam is a benzodiazepine. It is approved for the treatment of panic disorder (with or without agoraphobia), as well as certain types of seizure disorders. However, benzodiazepines are also commonly used to treat difficulty sleeping and alcohol withdrawal.
Panic Disorder occurs when a person experiences unexpected and repeated episodes of intense fear. These episodes have physical symptoms including chest pain, shortness of breath, heart palpitations, sweating, dizziness, and nausea. Fear of future episodes is also part of panic disorder.
What Is The Most Important Information I Should Know About Clonazepam?
Do not drive a car or operate machinery until you know how this medication affects you because you may notice that you feel tired or dizzy.
When starting clonazepam, anxiety or insomnia may improve rapidly or over a period of days.
Benzodiazepines, such as clonazepam, are often used for short periods of time only. They may produce emotional and/or physical dependence (addiction) even when used as recommended. With input from you, your health care provider will assess how long you will need to take the medicine.
Do not stop taking clonazepam or change your dose without talking to your health care provider first. Stopping clonazepam abruptly may result in one or more of the following withdrawal symptoms: irritability, nausea, tremor, dizziness, blood pressure changes, rapid heart rate, and seizures. Withdrawal reactions may occur when dosage reduction occurs for any reason.
The use of clonazepam with drugs like opioid medications has led to serious side effects including slowed, difficult breathing and death. Opioids are used to treat pain and include medications such as: codeine, oxycodone, morphine, and illegal drugs like heroin. Some opioid medications are also found in cough syrup.
If you are taking clonazepam with an opioid medication, get medical assistance immediately if you feel dizziness, sleepiness, have slow or troubled breathing, or if you pass out. Caregivers must get medical help right away if a patient does not respond and does not wake up.
Avoid alcohol while taking this medication.
Are There Specific Concerns About Clonazepam And Pregnancy?
If you are pregnant or planning to become pregnant, notify your health care provider to best manage your medications. People living with anxiety disorders who wish to become pregnant face important decisions regarding risk versus benefit of benzodiazepine use in pregnancy. Clonazepam can increase the risk of premature birth and low birth weight. Newborn withdrawal and “floppy baby syndrome” are other possible side effects. It is important to discuss this with your doctor and caregivers.
Regarding breastfeeding, caution is advised since clonazepam does pass into breast milk.
What Should I Discuss With My Health Care Provider Before Taking Clonazepam?
- Symptoms of your condition that bother you the most
- If you have thoughts of suicide or harming yourself
- Medications you have taken in the past for your condition, whether they were effective or caused any adverse effects
- If you experience side effects from your medications, discuss them with your health care provider. Some side effects may pass with time, but others may require changes in the medication.
- Any other psychiatric or medical problems you have including obstructive sleep apnea
- All other medications you are currently taking (including over the counter products and herbal and nutritional supplements) and any medication allergies you have
- Other non-medication treatment you are receiving such as talk therapy or substance abuse treatment. Your provider can explain how these different treatments work with the medication.
- If you are elderly or are prone to falls
- If you are pregnant, plan to become pregnant, or are breastfeeding
- If you have acute narrow-angle glaucoma or untreated open-angle glaucoma
- If you have liver disease
- If you have phenylketonuria (PKU)
- If you drink alcohol or use drugs
How Should I Take Clonazepam?
Clonazepam may be taken with or without food. Take with food if you experience an upset stomach.
Clonazepam may be taken every day at regular times or on an as needed (“PRN”) basis. Typically, your health care provider will limit the number of doses you should take in one day.
Your health care provider will determine the dose and method of taking the medication that is right for you based upon your response.
Clonazepam oral disintegrating tablets must remain in their original packaging. Open the package with clean dry hands before each dose. Do not try to put tablets in a pillbox if you take the orally disintegrating tablets. Take the tablets right away, do not store for later use.
Clonazepam oral disintegrating tablets will dissolve in your mouth within seconds and can be swallowed with or without liquid.
If you take the medication every day (instead of ‘as needed’), use a calendar, pillbox, alarm clock, or cell phone alert to help you remember to take it. You may also ask a family member or friend to remind you or check in with you to be sure you are taking your medication.
What Happens If I Miss A Dose Of Clonazepam?
If you miss a dose of clonazepam, take it as soon as you remember, unless it is closer to the time of your next dose. Discuss this with your health care provider. Do not double your next dose or take more than what is prescribed.
What Should I Avoid While Taking Clonazepam?
Avoid drinking alcohol and using illegal drugs while you are taking clonazepam. They may decrease the benefits (e.g., worsen your condition) and increase the adverse effects (e.g., sedation) of the medication. Alcohol increases the risk of accidental overdose with medications like clonazepam.
What Happens If I Overdose With Clonazepam?
If an overdose occurs call your doctor or 911. You may need urgent medical care. You may also contact the poison control center at 1-800-222-1222.
Symptoms of overdose include confusion, impaired coordination, slow reflexes, coma, and death.
A specific treatment to reverse the effects of clonazepam does exist. This medicine, called flumazenil, can reverse the effects of clonazepam but must be given through an IV at a hospital. Only a doctor can decide if you need this medication.
What Are The Possible Side Effects Of Clonazepam?
Common side effects
- Feeling dizzy, drowsy, fatigued, or lightheaded
- Impaired coordination, decreased ability to concentrate
If you experience these side effects after starting clonazepam they will often improve over the first week or two as you continue to take the medication. If side effects do not improve or become problematic, consult your health care provider.
Rare/serious side effects
Shortness of breath, trouble speaking, feeling very tired, dizziness, or passing out.
Increased heart rate, headache, memory impairment, irritability, and restlessness may occur.
Some people taking benzodiazepines develop a severe allergic reaction and swelling of the face. This can occur as early as with the first dose.
Some people taking benzodiazepines for sleep have experienced various behaviors while they were asleep/not fully awake, such as sleep driving, making phone calls, and preparing or eating food. The individuals have no memory of the events when they awaken.
Signs of feeling depressed or low mood, thoughts of harming or killing yourself, or lack of interest in life.
Are There Any Risks For Taking Clonazepam For Long Periods Of Time?
Clonazepam is a safe and effective medication when used as directed. Benzodiazepines may produce emotional and/or physical dependence (addiction) even when used as recommended. Physical dependence may develop after 2 or more weeks of daily use. The risk of withdrawal reactions when stopping therapy with clonazepam is increased with prolonged use of the medication.
What Other Medications May Interact With Clonazepam?
The following medications may increase the levels and effects of clonazepam:
- Ketoconazole (Nizoral®), itraconazole (Sporanox®), nefazodone (Serzone®), fluvoxamine (Luvox®), cimetidine (Tagamet®), and ritonavir (Norvir®)
The following medications may decrease the levels and effects of clonazepam:
- Carbamazepine (Tegretol®), phenytoin (Dilantin®), and phenobarbital (Luminal®)
Clonazepam should not be taken with other benzodiazepine medications.
Clonazepam may cause drowsiness, so caution should be used when combining it with other medications that cause drowsiness. These could include:
- Antihistamines such as diphenhydramine (Benadryl®)
- Narcotic pain medication such as morphine, oxycodone (OxyContin®), and hydrocodone (Vicodin® and Lortab®)
- Opioid cough medications such as codeine cough syrup
- Sleeping medications such as zolpidem (Ambien®)
- Other anti-anxiety medications, antipsychotic medications, certain anticonvulsant medications, and tricyclic antidepressant medications (such as amitriptyline)
How Long Does It Take For Clonazepam To Work?
When starting clonazepam, anxiety or insomnia may improve rapidly or over a period of days or within hours of the first dose of medication.
Summary of FDA Black Box Warnings
The FDA has found that benzodiazepines, such as clonazepam, when used in combination with opioids or other sedating medications can result in serious adverse reactions including death. Patients, and caregivers of these patients, should seek immediate medical attention if the patient starts to experience unusual dizziness or lightheadedness, extreme sleepiness, slow or difficult breathing, or unresponsiveness.
As a benzodiazepine, clonazepam comes with the risk of abuse, misuse, and addiction to the medication. Physical dependence to clonazepam can occur with prolonged use of the medication. A withdrawal reaction may occur when stopping clonazepam, but this risk can be reduced by slowly reducing the dose of clonazepam when stopping. Do not stop taking clonazepam abruptly, and do not make any changes to therapy without consulting your health care provider.
©2022 The American Association of Psychiatric Pharmacists (AAPP) and the National Alliance on Mental Illness (NAMI). AAPP and NAMI make this document available under the Creative Commons Attribution-No Derivatives 4.0 International License. Last Updated: January 2016.
This information is being provided as a community outreach effort of the American Association of Psychiatric Pharmacists. This information is for educational and informational purposes only and is not medical advice. This information contains a summary of important points and is not an exhaustive review of information about the medication. Always seek the advice of a physician or other qualified medical professional with any questions you may have regarding medications or medical conditions. Never delay seeking professional medical advice or disregard medical professional advice as a result of any information provided herein. The American Association of Psychiatric Pharmacists disclaims any and all liability alleged as a result of the information provided herein.