As an addenum to previous message--have had this cough for 18 months and been to respirologist to no avail

Atenolol can cause a dry cough-check with your doctor for his/her recommendations.

I'm assuming Atenelol is an ace inhibitor. All the ace inhibitors can cause a dry cough. Some people get used to it after a while, or it goes away. For some, it remains problematic. Occasionally a switch to another ace inhibitor will work, but frequently if the cough persists and you don't feel like you want to live with it, you need to switch the type of BP medication to either a beta blocker or a calcium channel blocker.