I have been on atenolol for quite some time and have been on Atkins about 4 months. I never had any physical problems from combining the two; however, my weight loss has been extremely slow! Dr. Atkins' book mentions that beta blockers can inhibit weight loss, and I found some articles in the medical literature that confirm this. So, very recently I asked my cardiologist if I could go off my atenolol for a while to see if my weight loss improved. Since I was on a beta blocker for heart rate control rather than blood pressure problems, I thought perhaps it might be safe to leave it off for a while. My doctor agreed to let me try this because he knows how faithful I've been to this WOE with not as much success as we'd both like. I think he had early doubts about the effect of Atkins on my lipids, but all has been well, and my triglycerides have fallen dramatically, so he has let me proceed. I haven't been without my beta blocker very long, so I don't yet know if this experiment will work, but other than having a slightly higher heart rate than before I've not experienced any physical problems. I do think it is a very good idea to level with your doctor about whatever you're doing about diet. Also, I would never "meddle" with my medications without talking with him about it!
Good luck!
Brenta