Rantac 150 Tablet is a medicine that reduces the amount of acid your stomach makes. It is used to treat and prevent heartburn, indigestion, and other symptoms caused by too much acid in the stomach. It is also used to treat and prevent stomach ulcers, reflux disease, and some rarer conditions. Rantac 150 Tablet is also commonly prescribed to prevent stomach ulcers and heartburn seen with the use of painkillers. The medicine must be taken in dose and duration as prescribed by the doctor. How much you need, and how often you take it, will depend on what you are being treated for. Follow the advice of your doctor. This medicine should relieve indigestion and heartburn within a few hours and you may only need to take it for a short time when you have symptoms. If you are taking it to prevent ulcers and other conditions you may need to take it for longer. You should keep taking it regularly to prevent problems from happening in the future. You may be able to help improve your symptoms by eating smaller meals more often and avoiding spicy or fatty foods.Most people who take it do not have any side effects but the most common include headache, constipation, feeling drowsy or tired, and diarrhea. If you do get a side effect, it is usually mild and will go away when you stop taking this medicine or as you adjust to it. Consult your doctor if any of these side effects bother you or do not go away.Before taking it, you should tell your doctor if you have any kidney or liver problems. This may affect the dose or suitability of this medicine. Also tell your doctor what other medicines you are taking as some may affect, or be affected by, this medicine. This medicine is usually considered safe to take during pregnancy and breastfeeding if it has been prescribed by a doctor. Avoid drinking alcohol as this can increase the amount of acid in your stomach and make your symptoms worse.