i don't usually suffer from allergies... only whenever i've gone a few weeks without getting my neck adjusted. i don't know why, but that's how it happens... during school, i get adjustments and my allergies don't bother me at all. but then, school ends and i don't get my adjustments and after about two weeks, i become an itchy, congested, red-eyed wreck. i can't wait til the studies on adjustments and allergies are completed.... there's a group of doctors in wisconsin trying to finish the study and get published.
either way, there haven't been any studies on long-term side effects of daily use of allergy medicines (obviously, since non-drowsy anti-allergy medicines are relatively new).