My oldest son is on Risperdal,as well as three other meds. He has done quite well with Allegra for seasonal allergies, and even better with Zyrtec. Zyrtec is OTC but allegra is not. Both are well tolerated with Risperdal. Benaadryl is not good with Risperdal. My son, age 17, is zonked out when he takes both. He basically is out like a light and doesn't wake up in the morning (until about 12 hours later) the few times he has taken it. Not good at all. Claritin does not work for him either, nor anyone in my family. I don't like Claritin and it has a side effect- nosebleeds- very bad...
You should try Zyrtec or Allegra.
Buy a good quality Quercetin 500mg at your health food store. It can be taken 3 times a day. It blocks histamine and leukotrienes. My son is on Risperdal and quercetin and does very well.
Eldermom