Allegra allergy medication is an antihistamine drug commonly used in allergy treatment. For those who are suffering with allergies, allegra may be the allergy medication that has the potential to provide quick allergy relief from allergies so you do not have to resign to a life of discomfort as earlier as you can. A word of caution though, allegra does and can cause certain kind of side effects after taking. The commonly reported side effects are nausea, drowsiness, vomiting, diarrhea and weakness. Before taking any allergy medicine, it is always better to consult a doctor first, and do not forget to follow the usage indications of the medication as in the package label or doctor’s instructions. If for whatever reason that you do not seem to have much improvement on your allergic conditions after taking the medications, it is better for you to look for doctor advices immediately.