ativan is the fastest acting of the benzos and so is good for people with panic attacks, I was given it 1 - 2 mg every 4 hours as needed. The max safe dose is 10 mg / day according to my pharmacist. It is also the most addictive of the class.

I'm now on clonazapam 1 mg 3 X daily and 2 mg at night, although most days I only wind up taking 1 mg in the am. I find it's good because though it's not as fast acting it stays in my system longer.