From the Guidelines
Ophthalmic antihistamines that are currently available include Emedastine (Emadine), Levocabastine (Livostin), Azelastine (Optivar), Epinastine (Elestat), Ketotifen (Alaway, Zaditor), and Olopatadine (Pataday, Patanol). These medications can be classified into different categories, including:
- Antihistamines: Emedastine (Emadine), Levocabastine (Livostin) 1
- Dual action agents (antihistamine and mast cell stabilizer): Azelastine (Optivar), Epinastine (Elestat), Ketotifen (Alaway, Zaditor), Olopatadine (Pataday, Patanol) 1 They work by blocking histamine receptors in the eye, reducing itching, redness, tearing, and swelling associated with allergic reactions. Some key points to consider when using these medications include:
- They come in various concentrations and dosing schedules, ranging from once-daily to four times daily administration 1
- Many of these medications are dual-acting, functioning both as antihistamines and mast cell stabilizers, which provides more comprehensive relief for allergic conjunctivitis symptoms 1
- Side effects are generally mild and may include temporary burning or stinging upon application, headache, and dry eyes 1
From the FDA Drug Label
Azelastine Hydrochloride Ophthalmic Solution, 0.05% is a sterile ophthalmic solution containing azelastine hydrochloride, a relatively selective H1-receptor antagonist for topical administration to the eyes. ANTIHISTAMINE EYE DROPS The following are ophthalmic antihistamines:
- Azelastine 2
- Ketotifen 3
- Emedastine is mentioned but no information about it being an antihistamine is provided in the given text.
From the Research
Ophthalmic Antihistamines
The following is a list of ophthalmic antihistamines mentioned in the studies:
- Azelastine 4
- Emedastine 4
- Ketotifen 4
- Levocabastine 4
- Olopatadine 4
- Antazoline (in combination with tetryzoline) 4
- Bepotastine besilate 4
- Mequitazine 4
- Nedocromil sodium (also has mast cell stabilizing properties) 4
- Sodium cromoglycate (also has mast cell stabilizing properties) 4
- Cetrizine (recently available as an ophthalmic solution) 5
Key Characteristics
These ophthalmic antihistamines are used to treat allergic conjunctivitis, with some also having mast cell stabilizing properties. They work by blocking histamine H1 receptors, reducing symptoms such as itching, redness, and tearing. The studies suggest that these antihistamines are effective in reducing symptoms of seasonal allergic conjunctivitis, with some also being safe and well-tolerated 4, 6. However, there is a need for more research on their long-term effects and potential impact on the ocular surface 6.