My RX Provider Suggested That I Take Atenolol 25 Mg

My RX provider suggested that I take Atenolol 25 mg instead of Bisoprolol Fumarate 5 mg due to lower cost. Was told they are the same medication. On second thought I have gotten a little concerned about the Atenolol 25 mg and was wondering what your opinion is. Thanks in advance for your feed back. I'm a 78 year old female.