Thank you for your question.
I am Dr Saha, I shall try my best to help you.
Atenolol usually have optimal effect in one to two weeks.
As you are still feeling tightness, thumping, you can inform your doctor.
He may increase the dose.
Side effects are there with atenolol.
But it does not happen always.
You need not to be concerned about it.
I hope this information helps.
If there’s anything else I can do, please let me know.
If you are satisfied, please rate my answer as good or excellent.