I thought I'd heard of it before, but i know it as Citalopram - my ex partner is on it for his bi-polar and it seems to work really well for him. And yep he certainly does pack on the weight when he's on it - it makes him eat like a horse!!
I also suffer from anxiety and in the past have always taken Aropax (Paroxetine) which works so well i've managed to drop my dose down to 10mg a day, which is very little, but I haven't had an anxiety/panic attack since a week after starting it this most recent time. Before that, in the 5 months prior I was up at the Emergency dept for anxiety a total of 18 times!!
One thing though, before i went back on Aropax this time around (I was reluctant to take it again because I had such a hard time coming off it the first time round), they tried me on Citalopram......well, I took it for two days and never touched it again - it made my anxiety way worse!!! I think this only happens to some people though, but just to let you know to be careful.
Good luck!!