Hi, Thanks for posting in HCM. I understand your concern. Allegra contains fexofenadine hydrochloride, which is an antihistamine used to treat allergic symptoms of seasonal allergic rhinitis (sneezing, runny nose, itchy or watery eyes) and urticaria (hives). Some common side effects of use Allegra include: nausea, diarrhea, stomach upset, muscle or back discomfort, sleepiness, headache and menstrual cramps. However, there aren t any specific studies documenting consequences of long-term Allegra use. There are no reported long term complications from use, although there is ongoing concern that it can lead to weight gain. It is known that the common first line allergy medications like Claritin, Zyrtec and Allegra are relatively safe. Since you have reduced the dose from the earlier dose you used to take, you may further reduce it if you are comfortable with, on consultation with your Physician. Hope the information provided would be helpful. All the best.