Class Name(s):

• 28:12.08 Benzodiazepines

Pronunciation:

• (kloe na' ze pam)

Brand Name(s):

• Klonopin^®; also available generically

IMPORTANT WARNING:

Clonazepam may increase the risk of serious or life-threatening breathing problems, sedation, or coma if used along with certain medications. Tell your doctor if you are taking or plan to take certain opiate medications for cough such as codeine (in Triacin-C, in Tuzistra XR) or hydrocodone (in Anexsia, in Norco, in Zyfrel) or for pain such as codeine (in Fiorinal), fentanyl (Actiq, Duragesic, Subsys, others), hydromorphone (Dilaudid, Exalgo), meperidine (Demerol), methadone (Dolophine, Methadose), morphine (Astramorph, Duramorph PF, Kadian), oxycodone (in Oxycet, in Percocet, in Roxicet, others), and tramadol (Conzip, Ultram, in Ultracet). Your doctor may need to change the dosages of your medications and will monitor you carefully. If you take clonazepam with any of these medications and you develop any of the following symptoms, call your doctor immediately or seek emergency medical care immediately: unusual dizziness, lightheadedness, extreme sleepiness, slowed or difficult breathing, or unresponsiveness. Be sure that your caregiver or family members know which symptoms may be serious so they can call the doctor or emergency medical care if you are unable to seek treatment on your own.

Clonazepam may be habit forming. Do not take a larger dose, take it more often, or for a longer time than your doctor tells you to. Tell your doctor if you have ever drunk large amounts of alcohol, if you use or have ever used street drugs, or have overused prescription medications. Do not drink alcohol or use street drugs during your treatment. Drinking alcohol or using street drugs during your treatment with clonazepam also increases the risk that you will experience these serious, life-threatening side effects. Also tell your doctor if you have or have ever had depression or another mental illness.

Clonazepam may cause a physical dependence (a condition in which unpleasant physical symptoms occur if a medication is suddenly stopped or taken in smaller doses), especially if you take it for several days to several weeks. Do not stop taking this medication or take fewer doses without talking to your doctor. Stopping clonazepam suddenly can worsen your condition and cause withdrawal symptoms that may last for several weeks to more than 12 months. Your doctor probably will decrease your clonazepam dose gradually. Call your doctor or get emergency medical treatment if you experience any of the following symptoms: unusual movements; ringing in your ears; anxiety; memory problems; difficulty concentrating; sleep problems; seizures; shaking; muscle twitching; changes in mental health; depression; burning or prickling feeling in your hands, arms, legs or feet; seeing or hearing things that others do not see or hear; thoughts of harming or killing yourself or others; overexcitement; or losing touch with reality.

WHY is this medicine prescribed?

Clonazepam is used alone or in combination with other medications to control certain types of seizures. It is also used to relieve panic attacks (sudden, unexpected attacks of extreme fear and worry about these attacks). Clonazepam is in a class of medications called benzodiazepines. It works by decreasing abnormal electrical activity in the brain.

HOW should this medicine be used?

Clonazepam comes as a tablet and an orally disintegrating tablet (tablet that dissolves quickly in the mouth) to take by mouth. It usually is taken one to three times a day with or without food. Take clonazepam at around the same time(s) every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand.

Do not try to push the orally disintegrating tablet through the foil. Instead, use dry hands to peel back the foil packaging. Immediately take out the tablet and place it in your mouth. The tablet will quickly dissolve and can be swallowed with or without liquid.

Your doctor will probably start you on a low dose of clonazepam and gradually increase your dose, not more often than once every 3 days.

Clonazepam may help control your condition, but will not cure it. It may take a few weeks or longer before you feel the full benefit of clonazepam. Continue to take clonazepam even if you feel well. Do not stop taking clonazepam without talking to your doctor, even if you experience side effects such as unusual changes in behavior or mood, If you suddenly stop taking clonazepam, you may experience withdrawal symptoms such as new or worsening seizures, hallucinating (seeing things or hearing voices that do not exist), changes in behavior, sweating, uncontrollable shaking of a part of your body, stomach or muscle cramps, anxiety, or difficulty falling asleep or staying asleep. Your doctor will probably decrease your dose gradually.

Are there OTHER USES for this medication?

Clonazepam is also used to treat symptoms of akathisia (restlessness and a need for constant movement) that may occur as a side effect of treatment with antipsychotic medications (medications for mental illness) and to treat acute catatonic reactions (state in which a person does not move or speak at all or moves or speaks abnormally). Talk to your doctor about the possible risks of using this medication for your condition.

This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

What SPECIAL PRECAUTIONS should I follow?

Before taking clonazepam,

• tell your doctor and pharmacist if you are allergic to clonazepam, other benzodiazepines such as alprazolam (Xanax), chlordiazepoxide (Librium, in Librax), clorazepate (Gen-Xene, Tranxene), diazepam (Diastat, Valium), estazolam, flurazepam, lorazepam (Ativan), midazolam (Versed), oxazepam, temazepam (Restoril), triazolam (Halcion), any other medications, or any of the ingredients in clonazepam tablets. Ask your pharmacist for a list of the ingredients.
• tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, and nutritional supplements you are taking or plan to take while taking clonazepam. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• the following herbal product may interact with clonazepam: St. John's wort. Be sure to let your doctor and pharmacist know that you are taking this medication before you start taking clonazepam. Do not start this medication while taking clonazepam without discussing with your healthcare provider.
• tell your doctor if you have or have ever had glaucoma (increased pressure in the eye that may cause vision loss) or liver disease. Your doctor may tell you not to take clonazepam.
• tell your doctor if you have or have ever had lung or kidney disease.
• tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. Clonazepam may harm the fetus. If you become pregnant while taking clonazepam, call your doctor.
• talk to your doctor about the risks and benefits of taking this medication if you are 65 years of age or older. Older adults should receive low doses of clonazepam because higher doses may not work better and may cause serious side effects.
• if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking clonazepam.
• you should know that this medication may make you drowsy. Do not drive a car or operate machinery until you know how this medication affects you.
• you should know that your mental health may change in unexpected ways, and you may become suicidal (thinking about harming or killing yourself or planning or trying to do so) while you are taking clonazepam for the treatment of epilepsy, mental illness, or other conditions. A small number of adults and children 5 years of age and older (about 1 in 500 people) who took anticonvulsants such as clonazepam to treat various conditions during clinical studies became suicidal during their treatment. Some of these people developed suicidal thoughts and behavior as early as one week after they started taking the medication. There is a risk that you may experience changes in your mental health if you take an anticonvulsant medication such as clonazepam, but there may also be a risk that you will experience changes in your mental health if your condition is not treated. You and your doctor will decide whether the risks of taking an anticonvulsant medication are greater than the risks of not taking the medication. You, your family, or your caregiver should call your doctor right away if you experience any of the following symptoms: panic attacks; agitation or restlessness; new or worsening irritability, anxiety, or depression; acting on dangerous impulses; difficulty falling or staying asleep; aggressive, angry, or violent behavior; mania (frenzied, abnormally excited mood), talking or thinking about wanting to hurt yourself or end your life, withdrawing from friends and family; preoccupation with death and dying, giving away prized possessions, or any other unusual changes in behavior or mood. Be sure that your family or caregiver knows which symptoms may be serious so they can call the doctor if you are unable to seek treatment on your own.

What SPECIAL DIETARY instructions should I follow?

Talk to your doctor about eating grapefruit and drinking grapefruit juice while taking this medicine.

What should I do IF I FORGET to take a dose?

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

What SIDE EFFECTS can this medicine cause?

Clonazepam may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• drowsiness
• dizziness
• unsteadiness
• problems with coordination
• difficulty thinking or remembering
• increased saliva
• muscle or joint pain
• frequent urination
• blurred vision
• changes in sex drive or ability

Some side effects can be serious. If you experience any of these symptoms or those listed in the IMPORTANT WARNING section, call your doctor immediately or get emergency medical treatment:

• rash
• hives
• swelling of the eyes, face, lips, tongue, or throat
• difficulty breathing or swallowing
• hoarseness
• difficulty breathing

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

What should I do in case of OVERDOSE?

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at http://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

Symptoms of overdose may include the following:

• drowsiness
• confusion
• coma (loss of consciousness for a period of time)

What should I know about STORAGE and DISPOSAL of this medication?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

Keep all medication out of sight and reach of children as many containers are not child-resistant. Always lock safety caps. Place the medication in a safe location - one that is up and away and out of their sight and reach. http://www.upandaway.org

Dispose of unneeded medications in a way so that pets, children, and other people cannot take them. Do not flush this medication down the toilet. Use a medicine take-back program. Talk to your pharmacist about take-back programs in your community. Visit the FDA's Safe Disposal of Medicines website http://goo.gl/c4Rm4p for more information.

What OTHER INFORMATION should I know?

Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your response to clonazepam.

Do not let anyone else take your medication. Clonazepam is a controlled substance. Prescriptions may be refilled only a limited number of times; ask your pharmacist if you have any questions.

Keep a written list of all of the prescription and nonprescription (over-the-counter) medicines, vitamins, minerals, and dietary supplements you are taking. Bring this list with you each time you visit a doctor or if you are admitted to the hospital. You should carry the list with you in case of emergencies.

This report on medications is for your information only, and is not considered individual patient advice. Because of the changing nature of drug information, please consult your physician or pharmacist about specific clinical use.

The American Society of Health-System Pharmacists, Inc. represents that the information provided hereunder was formulated with a reasonable standard of care, and in conformity with professional standards in the field. The American Society of Health-System Pharmacists, Inc. makes no representations or warranties, express or implied, including, but not limited to, any implied warranty of merchantability and/or fitness for a particular purpose, with respect to such information and specifically disclaims all such warranties. Users are advised that decisions regarding drug therapy are complex medical decisions requiring the independent, informed decision of an appropriate health care professional, and the information is provided for informational purposes only. The entire monograph for a drug should be reviewed for a thorough understanding of the drug's actions, uses and side effects. The American Society of Health-System Pharmacists, Inc. does not endorse or recommend the use of any drug. The information is not a substitute for medical care.

AHFS^® Patient Medication Information™ Copyright, 2025. The American Society of Health-System Pharmacists^®, 4500 East-West Highway, Suite 900, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.

Selected Revisions: May 15, 2021.