Ranitidine (Zantac) has several possible serious side effects that you need to bring to the attention of your medical practitioner as soon as you notice them. These are only possible problems which may occur in certain people and not all people may experience them. .Among these are chest pain, fever, green or yellowish cough discharge and shortness of breath. More side effects are bruising easily, bleeding and unusual weakness on your part. You might also have problems with your vision such as blurring. These are serious side effects that you must treat appropriately so go to the doctor if you are experiencing any of these. Zantac and high blood pressure may have a connection in the next side effects. You might experience either fast or slow heart rate after taking the drug Zantac. This is the serious side effect which has prompted several people to question the accuracy of Zantac and high blood pressure. The adverse effect of heightened or elevated blood pressure is sure to affect your hypertensive state if you do suffer from it. Therefore, some individuals have noticed adverse reactions when taking Zantac and high blood pressure prone. Other possible serious side effects of Zantac include nausea, vomiting, stomach pain, jaundice, low grade fever, appetite loss and clay colored stool. If you experience any of these during the time that Zantac is prescribed to you, it is best to consult your medical practitioner and request for another type of medication. I used to take this stuff but found out it was poisoning me, Doctors like to prescribe these tablets as they get incentives (bribes) from the drugs companies to do so, they will not admit it as it has gone on for so long they think it is their God given right, also have a look here. http://www.netdoctor.co.uk/medicines/100003829.html