I have taking Omep,Losec, or Domparion??? for the last 3 yrs. The major side effect for all 3 have been knee and calf cramps after going to bed. The morning starts with the cramps, and they are getting more frequent. I place a ice pack on the area, and it subsides for awhile. Hot baths seem to inflame the area. Any suggestions??? The acid refux is gone. I have taken myself off the medication, and the AR returns with a vengence. Interesting about the comment re: generic drugs, I hope you are wrong, as the insurance company that we have will only pay for the generic. When on group plan, I didn't care - but now...... Anyone else experience this? I am also on Lipitor, which have the leg cramp side effects??????