Olopatadine is:
Ref: Clinical Oculor Pharmacology, 1st ed. pg. 257* Olopatadine hydrochloride is an antihistamine (as well as anticholinergic and mast cell stabilizer)* It is used as eye drop to treat itching associated with allergic conjunctivitis.* Side effects include headache, eye burning and/or stinging, blurred vision, dry eyes, foreign body sensation, hyperemia, keratitis and taste perversion.
Mast cell stabilizer
Anti-histamine
Both mast cell stabilizer and anti histamine
None of the above
Endocrinology