This side effect is listed in most triptans ie imitrix, maxalt, amerge, frova, axert, and zomig. It is a rare side effect although it can happen it just rarely does. It usually occurs in people who have high blood pressure or heart disease and in that case they shouldn't be using these types of medicines anyway. From what I have been told it is an uncomforable feeling that lasts for a couple of hours and then goes away. It isn't a dying feeling just uncomfortable. Hope this helps some.