Famotidine
"I used to take famotidine 20mg 2 x daily and it did the job.  Now I need it every 5 to 6 hrs for relief.  So I decided to use Pepto-bismal yesterday morning at 8 and it worked very well and lasted until about 9pm. Then I took a Pepcid that night, but it doesn't work for me like it use to."