This is from David Nye, M.D. --

"A number of medications have been used to improve sleep in fibromyalgia. The oldest of these is amitriptyline (Elavil), a medication first used to treat depression. Amitriptyline and related medications probably work by improving the quality and depth of deep sleep rather than by any effect on mood. Although it probably works as well as any of the other medications, amitriptyline causes frequent bothersome side effects such as weight gain, dry mouth, daytime tiredness, and trouble concentrating more often than other medications with durations of action more appropriate for sleep so I usually try these other medications first. They include trazodone (Desyrel), diphenhydramine (Benadryl), cyclobenzaprine (Flexeril), alprazolam (Xanax), and carisoprodol (Soma).

Medication is started at a low dose and gradually increased until you sleep well at night and feel good during the day, encounter unacceptable side effects, or reach the prescribed maximum dose. Starting low and slow helps minimize initial side effects such as dizziness, nausea, and morning grogginess. By two to four weeks, most patients find that the side effects are settling down and the fibromyalgia symptoms are starting to improve.

It often takes a lot of fiddling with the dose to get it exactly right. It may be necessary to try several medications in succession or sometimes in combination. Some patients find that certain of these medications cause stimulation rather than sedation, as if one has had too many cups of coffee. When this "paradoxical effect" occurs it will be necessary to switch to another medication. Some medications may become less effective over time and the dose may then need to be increased slightly. Most patients will need to continue medication indefinitely, although sometimes the dose can be reduced once a good response to treatment has been achieved."

NOW, here are a couple of sites where you can look up your meds:

RxLIST - Comprehensive drug info
Pharmaceutical Information Network