Hello Flucloxacillin is a penicillin type antibiotics and this produces nausea , abdominal discomfort , epigastrium fullness , hyper acidity and so many other side effects. When such patient with with such gastric burning ( hyper acidity or gastritis ) I advise my patient to take pantoprazole with flucloxacillin ,both on empty stomach . With these two drugs ,you will not feel any side effects like heart burn or hyper acidity . But for hip surgery antibiotic is important so pantoprazole is also necessary for heart burn. Good luck.