Omeprazole cannot be taken orally together with amoxicillin. Omeprazole is a proton pump inhibitor, an acid suppressant, and is recommended to be taken orally half an hour before meals. Amoxicillin is a penicillin antibiotic and is best taken by mouth half an hour after a meal, so the two should not be mixed together. Omeprazole or other proton pump inhibitors, including gastric mucosal protectors and bismuth, are recommended to be taken orally half an hour before meals, which can improve the efficacy of the drugs. Amoxicillin or other antibiotics are recommended to be taken orally after meals to avoid adverse reactions in the gastrointestinal tract. Amoxicillin is used together with omeprazole and is indicated for H. pylori eradication treatment. An additional antibiotic, such as clarithromycin or ofloxacin, may be added, in consultation with a specialist. In short, acid suppressants and antibiotics should not be taken together.