You may need to stop taking certain medications before a nuclear test. For instance, your provider may tell you not to take beta-blockers, nitroglycerin, or heart medications for 24 hours before the test. You may also need to stop aspirin, blood thinners, asthma medications, and diabetes medications, 48 hours before the test. It's important that you tell your provider about all the medications you take, even over-the-counter ones.