For Allergic Rhinitis "I have severe seasonal allergies as well as severe allergies to dust and mold. I had gone through the gamut of second generation antihistamines (Claritin, Zyrtec and Allegra) with minimal success in treating my extreme symptoms. I decided to try the first generation antihistamine: Benadryl. Of course, it's been around for a long time, but it's definitely the most effective. The drawback to this older antihistamine is that it causes sleepiness, and it's not slight. Also, the newer antihistamines can be taken once a day, while Benadryl doses last only 4-6 hours. But to this extreme allergy sufferer, it's a small tradeoff, because it certainly treats the symptoms far better. "