Generic Zantac medication should be swallowed in pill form, or dissolved in six to eight ounces of water if an effervescent tablet. Pills are usually distributed in strengths of 150 mg or 300 mg of ranitidine. Effervescent tablets are distributed in 25 mg and 150 mg doses. Both medications should be stored in a dry, dark place at room temperature and kept away from children and pets. Recommended dosages are generally 150 mg, either once a day at bedtime or twice daily. As examples, maintenance healing of duodenal and gastric ulcers has an advised dosage of once daily 150 mg, and treatment for gastric ulcers is twice daily of the same amount. When you order Zantac online, be sure to check with your local physician about the correct dosage and frequency for your case. Antacids may be advised in cases where abdominal pain accompanies Zantac. Zantac may have uses apart from those listed, be sure to consult your local physician if you wish to buy Zantac online.