I have been taking Klonopin (my prescription is 1 mg, 3x a day) as needed for about a year. Before that, I was taking Ativan for about 2 years. I take Klonopin pretty infrequently, but if I have a panic attack I usually take 2 mg at once because 1 mg doesn't seem to calm me down. I had one of the worst panic attacks I've had in years tonight and took 3 mg at once for the first time. Should I be worried about overdosing or other potential side effects? I am on a few other meds as well. I have taken 2 mg of Klonopin at once many times and never had an adverse reaction.