GERD’s dirty little secret – When omeprazole's patent expired AstraZeneca launched the optically pure version esomeprazole, which is apparently four times as active and gave them a new patent and a corner of the acid reflux market. Bizarrely, both forms of the drug (pro-drug in fact) are converted to the same chemical in the body and so you could get the same efficacy level as esomeprazole simply by taking more of the original omeprazole, which of course is now available as a much cheaper generic since the AZ patent expired. Another opportunity for NHS or health insurance savings?