Drug Uses Zantac is used in the treatment of various gastrointestinal problems like GERD, erosive esophagitis, Zollinger-Ellison syndrome and systemic mastocytosis. Zantac is also used as a short term measure in the treatment of active ulcers. Usage Following the dosage instructions of your doctor is the best way to use any medication. If you are unsure or do not remember the instructions then you may read the medicine label for more detailed information. You may be prescribed an antacid along with Zantac. In that case you need to make sure that you space out the consumption of the two medicines by at least an hour. Please drink a full glass of water with Zantac. It is very important that you complete the dosage schedule and do not interrupt it in between without seeking prior consultation from your doctor. Taking your medication at the same time each day is a tried and tested method to avoid missing any doses. Missed Dose Despite your best attempts at remembering, if you still miss out on a dose, then take it as soon as you remember about it. But keep in mind that you will have to adjust your next dose by spacing it out by 4 to 5 hours. If this is not possible, then the best thing to do would be to skip the missed dose and continue with your normal dosage schedule. Never try to compensate for the missed dose by taking a double dose together. It may cause adverse effects. Storage Store Zantac at room temperature (read medicine label if unsure). Always keep it in a cool dark place that is not directly exposed to sources of heat or moisture and sunlight. Protect it from kids and pets. Overdose An overdose of Zantac may have adverse effects that require immediate medical attention. Contact the nearest emergency poison control center immediately if you notice effects like abnormal manner of walking, low blood pressure, fast heartbeat, restlessness and vomiting.