i have been on atenolol since september. i had occasional heartburn before that. ever since i have been on atenolol it has been worse. i was reading on internet things that cause or worsen heartburn, and betablockers were on there. i could not believe it. it says that they relax the LES and increase the reflux of stomach juices into the esophagus, contributing to heartburn. also ibuprofen is on the list to. i did not know any of this.