Hello,
For what it's worth, I was originally prescribed 0.25 mg to be taken twice a day as needed. My dosage was increased to 0.5mg to be taken twice a day as needed by the psychiatrist. I recently went to a physician for a wellness exam and told him the prescriptions I was taking and he was very knowledgeable in panic disorder. He had warned of withdraw symptoms or withdraw anxiety and recommended to me to take it twice a day at the same time every day.
Also, I have a workbook entitled "An End to Panic: Breakthrough Techniques for Overcoming Panic Disorder" by Elke Zuercher-White, Ph.D. (Harbinger self-help workbook). In this book under the medications chapter (specifically benzos) , it states " The dose is often started low to minimize or elmimate side effects, and is then increased to the level needed. If the doses are spaced too widely during the day, patients may experience "between dose" anxiety. This is the reason that short acting drugs such as Xanax and Ativan require multiple daily doses and the reason that many physicians favor longer acting ones such as Klonopin. The effective dose for Xanax, Ativan, and Klonopin is between 1 to 10 mg a day. The average effective dose is between 3 to 6 mg a day."
This is strictly my opinion and from what I have read. It will definitely depend on what your doctor decides. I personally take 0.5mg twice a day and I haven't noticed any zombie-like symptoms from it. I too, was worried about the same thing. The only time I do feel drowsy when I take clonazepam in the morning is if I don't have my morning coffee : ). Hope this helps and again, I'm not a doctor.