My husband has taken both in the past, and is still taking atenolol. He didn’t have any side effects from either one, and only stopped taking Norvasc because the base dropped it from their fomulary. Atenolol is a beta-blocker so it works by slowing down the heart and reducing its workload. If you have asthma you shouldn’t take it. Norvasc is a calcium channel blocker, so it works by relaxing the smooth muscle in the arterial wall, decreasing peripheral resistance and hence reducing blood pressure; in angina it increases blood flow to the heart muscle. They do different jobs so it may depend on what the cause of the high blood pressure is. In order to fully control his blood pressure my husband actually takes five different drugs, each affecting a slightly different aspect of the vascular system.