Patent ID: 7759355

Claim:
A method of treating restless legs syndrome, comprising administering an effective amount of at least one adenosine A2A receptor antagonist to a patient suffering from restless legs syndrome, which patient does not have Parkinson's disease, wherein the adenosine A2A receptor antagonist is a xanthine derivative or a pharmaceutically acceptable salt thereof, wherein the xanthine derivative is represented by the following formula (I-A): wherein R 1a and R 2a independently represent methyl or ethyl; R 3a represents hydrogen or lower alkyl; and Z a represents (in which at least one of R 7 , R 8 and R 9 represents lower alkyl or lower alkoxy and the others represent hydrogen; and R 10 represents hydrogen or lower alkyl) or (in which R 6 represents hydrogen, hydroxy, lower alkyl, lower alkoxy, halogen, nitro or amino; and m represents an integer of 1 to 3).