Lansoprazole may cause discomfort such as diarrhea, dry mouth, and nausea in the oral formulation and nausea, headache, and injection pain in the injectable formulation. Lansoprazole is a proton pump inhibitor and is available in both oral and injectable formulations. Among the common hazards of oral medications are diarrhea, dry mouth, nausea, xerostomia, abnormal taste, dizziness and headache, and less common are allergy, anemia, drowsiness, fever, and liver damage. Common hazards of injections are nausea, headache, pain at the injection site, followed by abdominal pain and diarrhea, abnormal sensation and taste. Lansoprazole is contraindicated in allergic persons and those who are taking atazanavir sulfate, whether to use the drug and the choice of dosage form should follow the guidance of the physician, if there are symptoms of discomfort after the use of the drug need to be promptly discontinued and handled by a physician.