You may experience some or none of the Zantac side effects explained in this article. Unfortunately, there is no way for your healthcare provider to know beforehand if you will have side effects from a medicine that you have never tried. Therefore, be sure to let your healthcare provider know if you develop any side effects during treatment. Also, let your healthcare provider know if you develop something that "just does not seem right." While it may not be a side effect of Zantac, your healthcare provider should be able to diagnose and treat the problem.