Manage your heartburn with Tagamet HB 200. Tagamet is the first Rx heartburn prevention product and has been trusted for over 40 years (1). It is FDA approved as a safe alternative to Ranitidine and is the only Cimetidine over-the-counter (OTC) brand with 200 mg acid reducer. Tagamet helps relieve and prevent heartburn associated with acid indigestion and sour stomach.