I took pepcid 3 hours ago and my heart burn is still on going. i am desperate for relief. i have zantac (ranitidine) 150. will it help if i take the zantac (ranitidine)?

Similar drugs: Pepcid and Zantac (ranitidine) are similar drugs because they are both histamine blockers. It's doubtful that Zantac (ranitidine) will give you significant relief if Pepcid didnt. Try Omeprazole instead which works differently (Prilosec). See your doctor ASAP as you likely need further evaluation.

You can try: Taking zantac (ranitidine) this one time after the recent pepcid, but should get an official eval by GI to see why you are getting such bad heart burn. You need to alter your diet, avoid trigger foods, increase fiber and water in your diet. But as stated, you need an eval as there are stronger medications that may be needed, not to mention the exam you should have (with possible testing) as previously stated.