<s>[INST] Hello Doctor, I would like to know about the side effects of the drug Lansoprazole. I have been taking this medicine orally for the last 17 years appx and I take this tablet every morning on an empty stomach....The dose which I take is 15mg. I take this drug for my reflux...Plz advise...Thank you [/INST] Hi, Lansoprazole is a proton pump inhibitor commonly prescribed to suppress the stomach acid production in the treatment of stomach ulcer, reflux disease, and other conditions. Its common side effects include diarrhea, osteoporosis (thinning of the bones), vitamin-B12 deficiency and increased risk of infections. I advise you to take vitamin-B12 and calcium supplements to prevent vitamin-B12 deficiency and osteoporosis. Hope I have answered your question. Let me know if I can assist you further.  </s>