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Olopatadine, sold under the brand name Patanol among others, is an antihistamine medication used to decrease the symptoms of allergic conjunctivitis and allergic rhinitis (hay fever). It is used as eye drops or as a nasal spray. It is an antihistamine and mast cell stabilizer. It is available as a generic medication.
Medical uses
Olopatadine is an active ingredient in eye drops designed to alleviate allergic conjunctivitis, a condition characterized by itchy, red, and watery eyes. It is intended to serve as a superior alternative to eye drops that contain corticosteroids. By utilizing olopatadine, the goal is to minimize the side effects associated with corticosteroids. These side effects include elevated intraocular pressure, which can lead to glaucoma, and an increased susceptibility to infections.
In nasal sprays, olopatadine is used either as a standalone active ingredient, or in a combination with mometasone, a corticosteroid. A fixed-dose combination of olopatadine hydrochloride 665 μg and mometasone furoate 25 μg is called "GSP301".
Side effects
Known side effects for olopatadine eye drops include headache, eye burning or stinging, blurred vision, dry eyes, foreign body sensation, hyperemia, keratitis, eyelid edema, pruritus, asthenia, sore throat (pharyngitis), rhinitis, sinusitis, taste perversion, and vomiting.
Olopatadine nasal spray may cause side effects such as nosebleeds, painful nasal sores, fever, urinary discomfort, nasal congestion, cough, throat irritation, a bitter taste, drowsiness, headaches, rashes, and repeated instances of painful urination.
Chemistry
Synthesis
thumb|center|500px|Olopatadine synthesis:
Pharmacology
Pharmacodynamics
Olopatadine acts as a selective antagonist of the histamine H<sub>1</sub> receptor, thus stabilizing mast cells and inhibiting histamine release.
History
Olopatadine was patented in 1986 by Kyowa Hakko Kogyo and came into medical use in 1997. It is also available as an oral tablet in Japan under the tradename Allelock, manufactured by Kyowa Hakko Kogyo.