No "non-drowsy" antihistamines are suitable for the treatment of an allergic reaction. Diphenhydamine(Benadryl) may make you sleepy, but sleepy and breathing is better then unresponsive and not breathing.
I always carry benadryl in my kits. I have the luxury of injectables, but childrens chewable benadryl is just about as good, you just need to make sure that you take the appropriate amount (25 - 50mg PO). Benadryl is VERY effectve in the treatment of severe allergic reactions and anaphylaxis. When our we rewrote our treatment protocols recently we gave benadryl a much higher priority then in the past. I have been able to withhold epinephrine (a medciation I don't like giving patients with pulses unless it is absolutely necisary)on many patients because benadryl worked.
Benadryl doesn't cause drowsiness in me, but I do carry loratadine(claritin)for "seasonal allergies" in others. It works great for the itchy eyes, runny nose, sneezing allergies. It just doesn't work on the major hives, difficulty swallowing, difficult breathing, swollen lips/airway... allergies.
I also like the versitlity of the drug; sleep aid (for many, not me

) antiemetic (anti-vomiting/nausea) and preventing motion sickness are all indictaions for benadryl. I like to call these three indications the long-car-trip-with-a-small-child indications.