Taking 40mg prescription prilosec daily and have breakthrough gerd which required zantac (ranitidine). do i need a new ppi?

Maybe...: If you are following strict dietary and lifestyle modifications routinely recommended to patients with gerd and are compliant with taking your Nexium (esomeprazole) it may be time to either try a different ppi or double the dose of nexium (esomeprazole). 30 - 40% of patients with gerd will require a double dose of ppi for control of symptoms. Make sure you are followed by a GI specialist. Good luck!