The medicine Atenolol belongs to a class of drugs known as Beta-blockers. Atenolol drug is a selective beta receptor antagonist. This group of drugs is used primarily to address cardiovascular diseases and hypertension. Atenolol works by slowing down the heart rate and relaxing blood vessels in order to decrease or lower blood pressure and to improve flow of blood across the body. Atenolol is a beta blocker medication used to treat hypertension or high blood pressure. It is an oral medicine for patients that that have been diagnosed with high blood pressure. The drug keeps the blood vessels dilated to lower the blood pressure and smooth blood flow. Once the pressure has been normalized, the hypertension condition will be treated. Atenolol can be used to treat other conditions associated with blood pressure such as angina especially after a heart attack. By treating high blood pressure, stroke and heart attack risks are also reduced. Not every patient can be treated by Atenolol since it has its complications too. If you have urination problem, you should avoid using this drug. The common side effects of this drug are vomiting, dizziness stomach upset, and pale skin.