There is absolutely no problem in taking a good brand (e.g. Atecard, Tensimin etc.) of atenolol alone. Please make sure that your mother continues on this medication. It is very dangerous to take a combination of atenolol with alprazolam because of a number of reasons including the possibility of addicition and other unknown side effects. A combination of atenolol with alprazolam is not only scientifically irrational but also illegal. It is being manufactured without mandatory approval from the Drugs Controller of India. The matter of such illegal combinations is being heard by a bench of Delhi High Court comprising Chief Justice himself.