Hi, Lasix (furosemide) and Lopressor (metoprolol) are both medications used to treat heart conditions such as high blood pressure and heart failure. While both medications have potential side effects, uncontrollable anger is not a commonly reported side effect of either medication. However, certain individuals may experience changes in mood or behavior as a result of taking medications, and this can vary from person to person. It is important to discuss any concerning symptoms with a healthcare provider, who can evaluate whether the medication may be contributing to the symptoms and make any necessary adjustments to the treatment plan. Additionally, it is possible that other factors, such as the stress of managing a chronic health condition or the recent hospitalization, may be contributing to your father s anger. Counseling or therapy may help address any emotional concerns. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Priyanka, General & Family Physician