Generic Aciphex, containing rabeprazole sodium, is a proton pump inhibitor used to treat gastro-esophageal reflux disease and peptic ulcers caused by H. pylori infection. It is important to follow dosage instructions carefully, typically taken once daily, and to consult a doctor regarding any other medications or health issues. Common side effects include nausea, diarrhea, and headache, and it is contraindicated in individuals with osteoporosis, chronic liver disease, or vitamin B12 deficiency.