Panic disorder with or without agoraphobia in adults. Panic disorder is a type of mental health condition that causes repeated panic attacks. Agoraphobia is a fear of being in places from which it may be hard to leave. Klonopin contains the active drug clonazepam. Klonopin comes as an oral tablet. The tablets are available in three strengths: 1 mg of Klonopin, and 2 mg of Klonopin.