Information on the drug ranitidine (Zantac) used in promoting healing of stomach and duodenal ulcers, heartburn, esophagitis, and Zollinger Ellison Syndrome. Side effects, drug interactions, and dosing information is provided. The active ingredient in Ranitidine Tablets, USP 150 mg and Ranitidine Tablets, USP 300 mg is ranitidine hydrochloride (HCl), USP, a histamine H 2-receptor antagonist. 150 mg PO twice daily. Symptomatic relief usually occurs within 24 hours after starting therapy. Although higher doses of ranitidine have been studied (300 mg PO twice daily), doubling the standard dose not improve efficacy; if a standard dose is not effective, consider alternate therapy (e.g., PPI). Ranitidine belongs to a group of drugs called histamine-2 blockers. It works by reducing the amount of acid your stomach produces. Ranitidine is used to treat and prevent ulcers in the stomach and intestines. Ranitidine is a prescription drug used to treat ulcers of the stomach and intestines. Learn about side effects, drug interactions, dosages, warnings, and more. La possibilité de malignité de la lésion devra êtr e exclue avant toute instauration de traitement chez les patients présentant un ulcère gastrique; le traitement par la ranitidine pouvant masquer les symptômes d'un carcinome gastrique. Ranitidine comes as a tablet, an effervescent tablet, effervescent granules, and a syrup to take by mouth. It is usually taken once a day at bedtime or two to four times a day. What is the active ingredient in Maximum Strength Zantac 150 ®? The active ingredient is ranitidine. What time of day should I take Maximum Strength Zantac 150® What is the active ingredient in Zantac 75 ®? The active ingredient is ranitidine. What time of day should I take Zantac 75 ®? Zantac 75 ® can be taken 30 to 60 minutes before eating food or drinking beverages that cause heartburn to prevent symptoms, or it can be taken when heartburn symptoms strike, providing relief in as little as 30. Ranitidine 150 mg tablets, the generic product of Zantac 150, is an over-the-counter medication used for the relief of heartburn and for the treatment of stomach ulcers.