I took famotidine for 4 days and then quickly got off...I started tappering off then went cold turkey since I hadnt taken it that long...i had already had a stomach virus with diahrrea which was aggravated by taking flovored pedialyte and then relieved by taking clear pedialyte...then taking nystatin for mouth ulcers which ensued after all this and it burned what i then noticed an ulcer hidden away..which got really bad below the breast bone and through my back..I have no gallbladder..anyway...I took famotidine and thought it was the nystatin bothering me..I had mood swings, extreme weakness and headache and left chest arm pain and neck pain...just a host of awful things...actually this medicine reacts very quickly...enough for me to start cutting it down by the end of the 2nd day...I was taking 20mgs twice a day....what a nightmare...the 5th day I went cold turkey and it caused me to have acid so bad even though I thought there wouldnt be any rebound....there was and it began to aggravate my ulcer even more...also that night I couldnt sleep...a sleep study had been done on me for snoring and they found i had nocturnal panic attacks...wow...I didnt sleep as a result that night..and by yesterday ...I was so uptight and hurting all over and knew after losing 12lbs I would be lucky to be alive...so I went to emergency...they did heart tests and did decide It was eppigastric...and i told them I felt hard things running along my spine in my back ...a comment was made had I ever heard that gall stones can still be present even when the gallbladder had been removed...wow that was a shocker...but...I had prayed so hard and had been praying and always do...but for myself which is odd to me...but the Lord more or less kept bringing to mind ..protonix....well, when I went in and they saw me...I heard the dr say...the emergency room dr...said, lets giver her some demerol and ativan and PROTONIX..wow...I knew then i was in the right place....I had taken protonix yrs earlier and it was great..however you can only stay on it a certain amount of time...right now I need to get to adr to see what is so bad in my esophagus or my duadenal area...so, i went to the cvs pharm and they gave me a generic form called pantoprazole...which is what protonix is...just not the brand name...i was worried that I might be allergic to some of its properties...but so far so good...usually the same meds are ok....it does feel so much better then a cox 2 inhibiter which is what your taking ..its an antihistamine type drug...normally i dont have that much trouble with antihystamines....well, you take care and pay attention to the side affects...cuz no one else does....