Not all triptans use the same ingredients, and often times it is the other
ingredients that people will have the adverse reactions to (for instance,
Imitrex is a Sulfa drug, and although most people with Sulfa antibiotic allergies don't end up having allergic reactions to Imitrex, it should still be noted that none of the other Triptans are Sulfa drugs).
There is a triptan called Naratriptan, the brand name is Amerge, and it tends to have much less adverse reactions than Imitrex.