Been getting brain zaps after 1 week on Allegra (fexofenadine). Had the same on Flonase. Is this something to be concerned about?

"Zaps"?Not sure, but. if you are worried about side effects, I can't connect the two; they are completely different medications. Allegra (fexofenadine) does not cross into the brain, even at 2-3x recommended doses; unlike other antihistamines, FAA allows flying a plane while on Allegra (fexofenadine). Flonase can cause side effects, but many other things would happen before a brain issue. Better check with your doctor.
Certainly . any substance or medicine that affects brain function is no good. But why you need these meds. For allergies we propose to treat the cause. To learn more about treating the cause visit us Our goal is to educate that by treating the cause you can get off medicines.