Discontinue the drug on reaction! Of course, how easy! Problem is that the patient is hypotensive, requiring pressor support or tachycardic requiring cardioversion (these are not hypothetical situations, they happened in the phase 2 trial). I'm an interventionalist in the middle of a case, the last thing I need is a nurse on speakerphone telling me that my other patient is crashing. The devil is in the details and this is exactly the kind of detail that cannot be blown off.