Clonazepam is used alone or together with other medicines to treat certain seizure disorders (eg, Lennox-Gastaut syndrome, akinetic, myoclonic, and absence seizures). It is also used to treat panic disorder. Clonazepam is a benzodiazepine that works in the brain to prevent seizures. Benzodiazepines are central nervous system (CNS) depressants, which are medicines that slow down the nervous system.

This medicine is available only with your doctor's prescription.

Take this medicine only as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered.

This medicine should come with a Medication Guide. Read and follow these instructions carefully. Ask your doctor if you have any questions.

Swallow the tablet whole with water.

If you are using the disintegrating tablet (wafer), make sure your hands are dry before you handle the tablet. Do not open the blister pack that contains the tablet until you are ready to take it. Remove the tablet from the blister pack by peeling back the foil. Do not push the tablet through the foil. Do not break or split the tablet. Place the tablet in your mouth. It should melt quickly. After the tablet has melted, you may take a sip of water.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

More common

Body aches or pain

chills

cough

difficulty breathing

discouragement

dizziness

ear congestion

feeling sad or empty

fever

headache

irritability

lack of appetite

loss of interest or pleasure

loss of voice

nasal congestion

poor coordination

runny nose

shakiness and unsteady walk

sleepiness or unusual drowsiness

sneezing

sore throat

tiredness

trouble concentrating

trouble sleeping

unsteadiness, trembling, or other problems with muscle control or coordination

unusual tiredness or weakness

Less common

Being forgetful

bladder pain

bloody or cloudy urine

change in speech

diarrhea

difficult, burning, or painful urination

frequent urge to urinate

general feeling of discomfort or illness

joint pain

loss of appetite

lower back or side pain

mood or mental changes

muscle aches and pains

nausea

nervousness

problems in urination or increase in the amount of urine

shivering

slurred speech

sore throat

sweating

trouble speaking

vomiting

Rare

Burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings

changes in skin color

chest pain or discomfort

cold sweats

colds

confusion

cough or hoarseness

difficulty with sleeping

dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position

excessive dreaming

excessive muscle tone

excitement

falling

fast, irregular, pounding, or racing heartbeat or pulse

feeling mad

feeling of unreality

flu-like symptoms

headache, severe and throbbing

lack of feeling or emotion

lack or loss of self-control

muscle stiffness

muscle tension or tightness

nightmares

pain, inflammation, or swelling in the calves, shoulders, or hands

pain or swelling in the arms or legs without any injury

pain, tenderness, or swelling of the foot or leg

partial or slight paralysis

scaling

sense of detachment from self or body

shakiness in the legs, arms, hands, or feet

skin rash

swelling around the eyes

swelling of the face, ankle, foot, or knees

thoughts of killing oneself changes in behavior

tightness in the chest

trembling or shaking of the hands or feet

uncaring

vision changes

Incidence not known

Abdominal pain or fullness

anxiety

black, tarry stools

bleeding gums

blood in the urine or stools

change in consciousness

chest congestion

difficulty with coordination

double vision

drowsiness

dry mouth

feeling that others are watching you or controlling your behavior

feeling that others can hear your thoughts

feeling, seeing, or hearing things that are not there

hyperventilation

irregular, fast, slow, or shallow breathing

irregular, twisting uncontrolled movement of the face, hands, arms, or legs

loss of interest or pleasure

loss of memory

loss of strength or energy

loss of voice

muscle weakness

pale or blue lips, fingernails, or skin

pinpoint red spots on the skin

problems with memory

restlessness

severe mood or mental changes

sores, ulcers, or white spots on the lips or in the mouth

swollen glands

troubled breathing with exertion

uncontrolled eye movements

unusual behavior

unusual bleeding or bruising

unusual weakness

vivid dreams

weight loss or gain

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less common

Decreased interest in sexual intercourse

difficulty with swallowing

dryness or soreness of the throat

heavy bleeding

hives

inability to have or keep an erection

longer than usual time to ejaculation of semen

loss in sexual ability, desire, drive, or performance

pain or tenderness around the eyes and cheekbones

puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue

voice changes

Rare

Acid or sour stomach

ankle, knee, or great toe joint pain

belching

bleeding after defecation

blistering, burning, crusting, dryness, or flaking of the skin

bloated

blurred or loss of vision

change in color perception

cracks in the skin at the corners of the mouth

decrease or change in vision

difficulty moving

double vision

dryness of the eyes

earache

excess air or gas in stomach or intestines

feeling of constant movement of self or surroundings

feeling of warmth

frequent bowel movements

full feeling

hair loss or thinning of the hair

halos around lights

heartburn

increased watering of the mouth

indigestion

irregularities in menstruation

itching in the genital or other skin areas

itching, scaling, severe redness, soreness, or swelling of the skin

joint stiffness or swelling

leg or muscle cramps

loss of taste

night blindness

nosebleeds

overbright appearance of lights

pain in the breasts or pelvic area

pain in the leg, nape, or back

passing gas

red, sore eyes

redness of the face, neck, arms, and occasionally, upper chest

redness or swelling in the ear

sensation of spinning

smaller amount of semen ejaculated than usual

sore on the edge of the eyelid

soreness or redness around the fingernails and toenails

stomach discomfort, upset, or pain

thickening of the tongue

thirst

tooth disorder

toothache

tunnel vision

twitching of the eyes

uncomfortable swelling around the anus

worsening of acne

Incidence not known

Burning feeling in the chest or stomach

difficulty having a bowel movement (stool)

increased appetite

increased hair growth, especially on the face

increased in sexual ability, desire, drive, or performance

increased interest in sexual intercourse

sore gums

tenderness in the stomach area

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

It is very important that your doctor check your progress at regular visits to see if the medicine is working properly and to allow for changes in the dose. Blood tests may be needed to check for unwanted effects.

Using this medicine while you are pregnant can harm your unborn baby. Use an effective form of birth control to keep from getting pregnant. If you think you have become pregnant while using the medicine, tell your doctor right away.

This medicine may be habit-forming. If you feel that the medicine is not working as well, do not use more than your prescribed dose. Call your doctor for instructions.

This medicine may cause drowsiness, trouble with thinking, trouble with controlling movements, or trouble with seeing clearly. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are not alert or able to think or see well.

If you develop any unusual and strange thoughts or behavior while you are taking clonazepam, be sure to discuss it with your doctor. Some changes that have occurred in people taking this medicine are like those seen in people who drink alcohol and then act in a manner that is not normal. Other changes may be more unusual and extreme, such as confusion, worsening of depression, hallucinations (seeing, hearing, or feeling things that are not there), suicidal thoughts, and unusual excitement, nervousness, or irritability.

If you have been taking this medicine for a long time, do not stop taking it without checking first with your doctor. Your doctor may want you to gradually reduce the amount you are using before stopping it completely. This may help prevent worsening of your condition and reduce the possibility of withdrawal symptoms, such as seizures, hallucinations, stomach or muscle cramps, tremors, or unusual behavior.

This medicine will add to the effects of alcohol and other central nervous system (CNS) depressants. CNS depressants are medicines that slow down the nervous system, which may cause drowsiness or make you less alert. Some examples of CNS depressants are antihistamines or medicine for hay fever, allergies or colds, sedatives, tranquilizers, or sleeping medicine, prescription pain medicine or narcotics, barbiturates or seizure medicines, muscle relaxants, or anesthetics (numbing medicines), including some dental anesthetics. Check with your doctor before taking any of these products while you are using this medicine.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.