Get emergency medical help if you have signs of an allergic reaction to Klonopin : hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Clonazepam can slow or stop your breathing, especially if you have recently used an opioid medication, alcohol, or other drugs that can slow your breathing. A person caring for you should seek emergency medical attention if you have weak or shallow breathing, if you are hard to wake up, or if you stop breathing.
Report any new or worsening symptoms to your doctor, such as: mood or behavior changes, anxiety, panic attacks, trouble sleeping, or if you feel impulsive, irritable, agitated, hostile, aggressive, restless, hyperactive (mentally or physically), more depressed, or have thoughts about suicide or hurting yourself.
Call your doctor at once if you have:
new or worsening seizures;
severe drowsiness;
weak or shallow breathing;
unusual changes in mood or behavior;
nightmares, hallucinations;
thoughts of suicide or hurting yourself;
unusual or involuntary eye movements.
The sedative effects of clonazepam may last longer in older adults. Accidental falls are common in elderly patients who take benzodiazepines. Use caution to avoid falling or accidental injury while you are taking Klonopin.
Common Klonopin side effects may include:
drowsiness, dizziness;
feeling tired or depressed;
memory problems; or
problems with walking or coordination.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
 Klonopin side effects (more detail)
