Always seek the advice of your health care professional if you have any questions about this product or your medical condition. Maintenance therapy for gastric ulcer patients at reduced dosage after healing of acute ulcers. Each Zantac 300 Tablet for oral administration contains 336 mg of ranitidine HCl equivalent to 300 mg of zantac kaufen on-line ranitidine. Com is for informational purposes only and is not substitute for medical advice or treatment for any medical conditions. The150-milligram effervescent tablet should be dissolved in to ounces of water. Effectiveness There have been several studies conducted to assess how effective the drug is for treating various conditions, including: Ulcers GERD Erosive esophagitis Certain pathological hypersecretory conditions. Overreacting in seeking medical help, they said, is always better than underreacting.