Clonazepam (Klonopin)

When is clonazepam used ?

Clonazepam is used alone or with other seizure medicines to treat absence and myoclonic seizures (especially in Lennox-Gastaut syndrome), and can help stop seizure clusters. (An example of a cluster might involve a person who has one complex partial seizure in the morning and three or four more seizures over the course of the day, once or twice per month.)

A person who typically has a prolonged warning before large seizures (a particular symptom, an unusually long aura, or a series of small seizures) may be able to prevent the larger seizure by taking clonazepam when the warning begins.

For seizures that mainly occur during sleep or shortly after awakening, giving clonazepam or another benzodiazepine at bedtime can be very effective in controlling the seizures and improving sleep.

Besides its use in epilepsy, in what other conditions is clonazepam used ?

Besides seizures, the U.S. Food and Drug Administration (FDA) has approved clonazepam for the treatment of panic disorder. It is also legal to prescribe medicines for "off-label uses" even though the FDA has not formally approved such uses. Clonazepam is sometimes used in this way to treat movement disorders such as Tourette’s syndrome.

What are the most common side effects of clonazepam ?

Clonazepam belongs to a class of medications called benzodiazepines. Benzodiazepines are tranquilizers (sedatives) that prevent or stop seizures by slowing down the central nervous system. This makes abnormal electrical activity less likely. As a result, common symptoms include:

  • fatigue
  • dizziness
  • unsteadiness
  • impaired attention and memory
  • irritability
  • hyperactivity (in children)
  • drooling (in children)
  • depression (usually in adults)
  • nausea
  • loss of appetite

Scientific studies show that about half of people treated for seizures with clonazepam experience drowsiness and about 30% have problems with coordination. In some cases, these problems diminish with time.

About 25% have behavioral problems; in children, this often manifests as hyperactivity. Problems with thinking and behavior are greater with clonazepam than with non-benzodiazepine seizure medicines.

If any of these symptoms do not go away within several days, or are truly bothersome, call the doctor. Sometimes the doctor can help with these side effects by changing the prescription:

  • reducing the overall amount of clonazepam
  • changing the amount taken at certain times, such as taking a greater proportion of the clonazepam at bedtime to reduce daytime sleepiness
  • prescribing smaller doses, at more frequent intervals

No one should stop taking clonazepam or change the amount or time of taking the medication without their doctor's guidance. Suddenly stopping the medication can be associated with repetitive breakthrough seizures.

People who have just started taking clonazepam (or who have just started taking a larger amount) should be careful during activities that require their full attention to ensure that they don’t become too sleepy on the new or higher dosage.

What are the most serious effects of clonazepam ?

Most people who take clonazepam have either no or mild side effects that generally disappear within a short time without lasting harm. Serious reactions are extremely rare but should be reported immediately. Serious symptoms for which a patient should call the doctor immediately are:

  • An allergic reaction (difficulty breathing; closing of the throat; swelling of the lips, face, or tongue; or hives)
  • Sores in the mouth or throat (a potential blood problem)
  • Yellowing of the skin or eyes
  • Rash
  • Hallucinations, severe confusion, or changes in vision

One of the great dangers in using medications like clonazepam is tolerance, or a lessening of the effect at the same dose over time. Therefore, there is a tendency to increase the dose as tolerance develops. To a certain extent, dosage increases may be necessary, but adverse effects may be increased more than seizure control. If the dosage is increased gradually over a long period, subtle changes in personality (such as irritability, depression, or decreased motivation) or problems such as impaired memory may go unnoticed or be considered normal for that person.

High doses sometimes are prescribed, especially for those with developmental disabilities. Problems with thinking and behavior may be the result. If the dose has been increased gradually over many months or years, it can be hard to separate the effects of clonazepam (or other benzodiazepines) from the effects of other medications, seizures, and other neurological and psychological disorders.

An important concern when people with epilepsy take clonazepam or other benzodiazepines is the risk of “withdrawal seizures” or increased, repetitive or more severe seizures if the medicine is reduced or stopped. Withdrawal symptoms usually begin upon stopping the medicine and last for 8 to 10 days. Early symptoms might be agitation, anxiety, restlessness or even fast heart rate, though seizures might begin immediately as well. The longer the person has been taking clonazepam and the higher the dose, the greater the tolerance and therefore the higher the risk of withdrawal seizures. Even small, gradual dose reductions can temporarily increase seizure activity, but your doctor may suggest these changes since the long-term decrease in effects like drowsiness and depression often makes this worthwhile.

Are there long-term side effects of taking clonazepam ?

Clonazepam and other benzodiazepines are the medicines that are most likely to cause psychological dependence. When someone takes a benzodiazepine at a certain dosage for more than 2 to 4 weeks, the body (or specifically, the brain's receptors for the neurotransmitter GABA) becomes accustomed to it. Then if a dose is missed or reduced, a withdrawal process starts and the person experiences:

  • anxiety
  • increased heart rate
  • tremor
  • general unwell feeling

Taking another pill relieves all of these symptoms, confirming the person's belief that he or she "needs" the medication. This is a very dangerous cycle, since long-term use can cause long-lasting changes in the brain's GABA receptors that lead to significant problems such as impaired thinking, decreased motivation, and depression. In this setting, rapid dose reduction can cause severe symptoms of anxiety, insomnia, and illness, as well as seizures. In many of these cases, very gradual reduction of the benzodiazepine (often over many months or years) can lead to a dramatic improvement in attention, concentration, memory, and mood without worsening the seizures, insomnia, or anxiety for which the medication was originally prescribed.