I've been taking Clonazepam for about two and a half years now. I felt its effects big time when I first started taking it. Now I think my body is becoming more immune to it, and they really don't help as much as I'd like.
And not only that, they take probably at least about 15-20 minutes to kick in even just a little bit. If I take my pill at the beginning of my panic attack (or when I suspect I will have an attack), it doesn't really help until the panic attack has passed. Then I just end up feeling groggy and sleepy.
I suppose it's better to have this drug, than to have none at all, though.
My post was pointless...