<unk>  is a H1 histamine receptor antagonist that is FDA approved for the prophylaxis of itching associated with allergic conjunctivitis.   Common adverse reactions include burning sensation in the eye, folliculosis, hyperemia, and pruritus, infection.
Epinastine hydrochloride
Bepotastine Besilate
Azelastine Hydrochloride
Azelastine 
Clemastine
Acrivastine
Pemirolast
Bosentan