Hi Fuzzy,

I wouldn't necessarily say that it's pooped out, but you may have adjusted to the dosage. Prescribing will sometimes start out at the lower end of the scale, with room to increase as needed until a theraputic dose is found.
Afterall they wouldn't usually start you on a high dosage as everyone can react to different medications differently, so safer to start lower.
And while for some 100mg may be just what they need, it obviously doesn't work that way for everyone. So please don't give up hope, there is plenty of room for the dosage to be increased, and hopefully they'll find a dosage/regime that works for you if this one doesn't

Alison