restless legs syndrome
"Restless Legs Syndrome in a nut-shell:  Find your trigger.  After a lot of experimentation, I've found that a number of things contribute to my RLS:
-fatigue
-iron-deficiency (possible other deficiencies)
-anxiety
-alcohol
... I'm sure there are more.

In any case, I did try this medication as sometimes I can't determine the cause.  It was awful!  It made me restless throughout the night.  I completely dried up.  Finally, when the medicine started to wear off, I could barely move around from extreme fatigue as though I never slept.  Sure it'll make you drowsy, but don't expect a goods nights rest.  I've since found that fighting restless legs syndrome is best by fighting the above triggers."