"Dr. Mario Online Rx (Dr. MARIO & 細菌撲滅 Dokutā Mario ando Saikin Bokumetsu, "Dr. Mario & Bacteria Extermination", Dr. Mario & Germ Buster in Europe and Australia) is a puzzle video game starring Dr. Mario. It was one of the WiiWare launch games in Japan, Europe, and Australia, and was released on March 25, 2008 (Japan) and May 20, 2008 (Europe/Australia). It was released in North America on May 26, 2008. It costs 1000 Wii Points and takes up 103 Blocks.
Although registered with the ESRB as Dr. Mario Wii, a short clip of the game from the Nintendo Channel revealed its North American title before release. The letters "Rx" in the title refers to ℞, the common symbol for prescription."
Source: Wikipedia, "Dr._Mario_Online_Rx," available under the CC-BY-SA License.