I am scheduled to have a thalium stress test next week and have always been afraid of having new substances ingested or injected into me. Can you tell me if there are any side effects or allergic reactions I should be concerned with? I am allergic to non-steroidal anti-inflammatories. Thank you for your time. I hate being neurotic about this stuff, but once you have had an allergic reaction to something, you tend to always be afraid.