Com provides free, accurate and independent advice on more than 24,000 prescription drugs, over-the-counter medicines natural products. Absorption of online prevacid lansoprazole begins only after the granules leave the stomach. To receive the best possible health care, people are encouraged to gather information in one place and create personal medical record. If there is recurrence of erosive esophagitis, an additional week course of Prevacid may be considered. The most frequently reported at least treatment-related adverse reactions in these patients were headache abdominal pain nausea and dizziness. 4Rate it! Prevacid decreases the amount of acid produced in the stomach.