I take propanolol to stop the physical effects when im having a panic attack i am going to take a viagra (sildenafil) in a couple of hours is this ok ?

Here are some...: Yes, you may but caution is always needed in taking drugs exerting similar effect on the same organ or system, like both in this Q have individual effect to dilate blood vessel but in different mechanisms. In fact, the study on drug interaction is always incomplete because it is impossible to test one drug with all available drugs in the market. So, take them in 6-8 hrs apart and see; reasonable.