Well, if she keeps demanding more than is prescribed, the logic would seem that what is being prescribed isn't working!

The amount she's getting isn't calming her down!

I definitely think a trip to the GP is necessary - with you with her, to explain to the doctor what is happening at home, and how bad your wife is getting. The doc will either prescribe a higher dose, or put her on something else.

Why do you think your wife is getting panic attacks? Are they actually 'about' anything (other than a desperation to take more diazepam!)