I was told that metroprolol is a selective beta blocker and does not target lung receptors but at the same time I was told to take the lowest possible dose (under 100mg). I can't take other blood pressure meds for various reasons including kidney issues and leg swelling caused by calcium channel blockers. The only way to keep by bp lower is a combo of clonidine patch and metroprolol succ. er. I do have asthma. It's really hard to know what to do in my situation. (I have autoimmune disease also). Right now I am having a flare up and I worry it is the bp med but this allergy season was the worst ever so ....right now I am on doxy and extra oral prednisone starting today. I hope it works! Things get dicey when you have multiple competing problems!