My wife who has Fibro was taking five Vicadon hp's and 8 Ultrams for about a year. They worked good for awhile and then her tolerance went up and the pain increased. Four days ago her Doctor put her on Methadone 10 mgs 4 times a day and told her to continue with the Ultram. Ever since she started with the Methadone, her fatigue has greatly increased. She hasn't even taken more than 2 or 3 a day. Is this common with Methadone? If it is how long does it usually take to adjust to this drug?