Trade/other name(s): Klonopin
Why would this drug be used?
Clonazepam is used to manage panic attacks, seizures, and other conditions.
How does this drug work?
Clonazepam is an anti-anxiety agent that belongs to a group of drugs called benzodiazepines. This group of drugs slows down the brain and nervous system by locking down certain chemical signals (neurotransmitters) in the brain. Like alcohol, opioids, and several other types of medicine, these drugs are considered to be central nervous system depressants. They slow down the brain and body, causing the patient to feel calm and relaxed.
Before taking this medicine
Tell your doctor…
- If you are allergic to anything, including medicines, dyes, additives, or foods.
- If you have any medical conditions such as kidney disease, liver disease (including hepatitis), heart disease, congestive heart failure, seizures, or brain disease. These conditions may require that your medicine dose, regimen, or timing be changed.
- If you have asthma, emphysema, bronchitis, sleep apnea, or other breathing problem. This medicine can worsen breathing.
- If you have depression, myasthenia gravis, or porphyria. This medicine may make the symptoms worse.
- If you have glaucoma. People with acute narrow-angle glaucoma should not use this drug.
- If you are taking any medicine that makes you calmer or drowsy (sedative), or if you drink alcohol. The combination may produce serious side effects.
- If you have ever had a problem with alcohol or addiction in the past. This drug can be habit forming, and those with previous addictions are more at risk.
- If you are pregnant, trying to get pregnant, or if there is any chance of pregnancy. There may be an increased risk of harm to the fetus if a woman takes this drug during pregnancy. In addition, newborns whose mothers take the drug regularly in late pregnancy may have withdrawal symptoms after birth.
- If you are breast-feeding. The drug may pass into breast milk and harm the baby.
- About any other prescription or over-the-counter medicines you are taking, including vitamins and herbs. In fact, keeping a written list of each of these medicines (including the doses of each and when you take them) with you in case of emergency may help prevent complications if you get sick.
Interactions with other drugs
Clonazepam should not be taken with itraconazole or ketoconazole. They can cause clonazepam to build up in the blood and cause serious effects.
The drugs nefazodone (Serzone) and fluvoxamine (Luvox) can cause clonazepam to build up in the body, raising the risk of serious side effects. If you need one of these medicines, your doctor may be able to adjust your clonazepam dose.
This medicine will add to the effects of other medicines or substances that make you sleepy or less alert, such as:
- tranquilizers (sedatives)
- sleeping pills
- muscle relaxers
- anti-seizure medicines
- opioid pain medicines
- anti-psychotic drugs
- certain anti-nausea medicines
Using these kinds of substances while taking clonazepam can result in losing consciousness (passing out) and possibly death.
Some anti-seizure drugs (such as phenytoin, carbamazepine, and phenobarbital) may make your body get rid of clonazepam faster.
Check with your doctor, nurse, or pharmacist about whether other medicines, vitamins, herbs, and supplements can cause problems with this medicine.
Interactions with foods
No serious interactions with food are known at this time. Check with your doctor, nurse, or pharmacist about whether foods may be a problem.
Tell all the doctors, dentists, nurses, and pharmacists you visit that you are taking this drug.
How is this drug taken or given?
Clonazepam is a pill taken by mouth 1 to 3 times a day. The last dose is usually taken at bedtime. Take the pill with or without food, and try to take it at the same times each day. The dose depends upon your size and the reason you are taking the medicine.
Take this drug exactly as your doctor tells you to. If you do not understand the instructions, your doctor or nurse can explain them to you. Store the medicine away from heat and moisture and away from children, pets, and other people.
If you are taking the clonazepam wafer that melts in the mouth, handle it with dry hands. If you only take part of a wafer, throw out the rest right away.
Avoid drinking alcohol while taking clonazepam.
This drug can interact with a number of other medicines and should be used cautiously (if at all) in people with a number of different medical conditions. See the "Before taking this medicine" section of this document for more detailed information.
Clonazepam may make you feel drowsy or dizzy. This is more likely if you are taking other drugs that depress your nervous system such as opioids, anti-anxiety drugs, muscle relaxers, or some anti-nausea medicines. Do not drive or operate heavy machinery until you know the effect the drug will have. Talk to your doctor or nurse if you feel too drowsy or have dizziness that does not go away.
As with other anti-seizure medicines, this drug may raise the risk of suicidal thoughts and actions, mostly in people under age 25. This is more common during the first few months of treatment. If you notice any strange or unusual thoughts or behavior, such as irritability, sleep problems, aggressiveness, restlessness, panic attacks, or thoughts of suicide while on this medicine, call your doctor. Tell family members, loved ones, and caregivers that you are taking this drug, so that they can help you if they notice behavior changes.
This is a controlled substance, and may be habit-forming. Take clonazepam only as directed by your doctor. Clonazepam may cause physical dependence (your body goes into withdrawal if the drug is suddenly stopped). Signs of physical dependence are common when the drug is taken for more than a few weeks. Physical dependence can be managed by stopping the medicine gradually over time. A few people also become psychologically dependent on clonazepam, which can lead to addiction. Some signs of psychological dependence are a strong desire to keep taking the medicine and wanting larger doses of the medicine. Talk with your doctor if you think this is happening to you.
Do not stop taking this drug without talking with your doctor. If you have been taking this drug for more than a few weeks, you may experience withdrawal symptoms for several days if you stop it suddenly. Most often this appears as irritability, nervousness, trouble sleeping, stomach cramps or upset stomach, trembling or shaking, and even hallucinations and seizures in those who have taken high doses for a long time. Talk with your doctor or nurse about stopping the drug by carefully lowering the dose over time.
Tell anyone who is planning surgery on you, including dentists, that you are taking this medicine.
Rarely, people get confused, agitated, or start seeing or hearing things that are not there (hallucinations) while on this medicine. Call your doctor if you have these problems, or if you have seizures, shuffling walk, restlessness or tremor, fever, irregular heart rate, yellow skin or eyes.
Older people are more likely to be sleepy, dizzy, confused, or fall while taking clonazepam. Have another responsible adult with you for a few days after you start this medicine and any time you change doses.
Rarely, allergic reactions happen with this medicine. Call your doctor if you notice a severe rash, swelling in the mouth, face, or throat, or trouble breathing or swallowing.
Rather than getting calmer, a few people respond to the drug in the opposite way, and become irritable, nervous, excited, anxious, hostile, and less sleepy. If this happens, call your doctor or nurse.
If you think that you or someone else may have taken an overdose of this medicine, get emergency help right away. Taking too much clonazepam, or taking it with alcohol or any other medicine that slows the nervous system can cause confusion, severe drowsiness or weakness, trouble walking or talking, loss of consciousness, and sometimes death.
Possible side effects
You will probably not have most of the following side effects, but if you have any talk to your doctor or nurse. They can help you understand the side effects and cope with them.
- trouble walking or keeping your balance
- decrease in blood pressure when changing position
- decreased mental alertness
- poor coordination
- trouble speaking
- problems with memory
- mood changes
- change in activity level
- decreased appetite
- heart palpitations*
- chest pain
- swelling in feet
- acne flare–ups
- change in sexual interest
- withdrawal symptoms if drug is stopped suddenly, such as anxiety, irritation, nausea, trouble sleeping, shaking, hallucinations, seizures*
- allergic reaction*
*See "Precautions" section for more detailed information.
Yes – first approved before 1984 (FDA cannot verify dates of drugs approved before 1984).
Disclaimer: This information does not cover all possible uses, actions, precautions, side effects, or interactions. It is not intended as medical advice, and should not be relied upon as a substitute for talking with your doctor, who is familiar with your medical needs.
Last Revised: 10/02/2009