Sir—With the medications you have listed, there are no interactions with Zantac. In regards to indigestion, the recommended dose of Zantac is to start off with a 75 mg tablet about 30-60 minutes before eating food or drinking any beverage that cause heartburn. Zantac will help in preventing heartburn. The maximum amount to take in one day is 300 mg (4 tablets of 75 mg or 2 tablets of 150 mg). You should not use it for more the 14 days or on a regular basis unless consulting with a physician.