Can i take 3 zantac (ranitidine) at one time?

Not recommended: Risks outweigh benefits. Taking three 150 mg pills probably would not cause toxicity though it also would not likely provide more relief. Current recommended dosages for Zantac (or ranitidine) for most conditions is 150 mg twice daily or 300 mg once at bedtime. Patients with erosive esophagitis may benefit from 150 mg four times daily but dosages are about every 6 hours, not all at once.