I have Cluster headaches. My Neurologist wrote a presciption for Imitrex injections. Careless, I mean caremark-CVS would only fill 2 shots per month. When I called to ask why the rep told me it was a controlled substance and it was not due to the high cost. I told my doctor and he said the were lying that it is not a controlled substance.I guess they make more money from the companies that hire them(AT&T) if they don't fill the expensive prescriptions!