Actually it is the decongestants you should watch out for... ok just ask the pharmacist. Benedryl (at night) works for me. I take adderall.
What allergies does you son have. My daughter is allergic to grass, pollen, dust, mold, ragweed, and animal dander. she is on Rhino-cort nasal spray and zertec and even has asthma. She was on Ritalin LA over 7 months before the switch to concerta and I miss the ritalin liked it better. It was switched because the next dose up was too high so concerta was higher yet less.Okay I will ask the pharmacist to make sure.I've been through the allergy thing myself. All allergy pills are fine as long as they don't contain antihistamine. The allergy pills don't (allegra, etc.) as they treat the cause not the symptoms. I went to the pharmacist and he said that as long as it's not a combination allergy pill/antihistamine it's totally safe. Just check the label and make sure it doesn't have either pseudoephedrine or dextromethorphan. Either one can raise the heart rate and blood pressure and will cause trouble.
Remember that allergy pills take time (I think at least 2 weeks) to work. Give them time to build up so that they can work.