Hi, Atenolol is a beta-blocker medication used to treat high blood pressure (hypertension) and certain heart conditions. Both Aten 50 and Aten AM contain atenolol, but Aten AM also contains another medication called amlodipine, which is a calcium channel blocker used to treat hypertension and angina. In cases of high blood pressure that are difficult to control with a single medication, combination therapy with two or more medications from different drug classes may be necessary. A combination of atenolol and amlodipine can be effective in reducing blood pressure, and the combination of these medications is commonly used. In the situation you described, your mother s doctor may have prescribed Aten AM instead of Aten 50 to provide additional blood pressure-lowering effects and potentially improve her overall cardiovascular health. However, it is important to follow the doctor s instructions and attend follow-up appointments to monitor the effectiveness of the medication and any potential side effects. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Priyanka, General & Family Physician