Olopatadine, sold under the brand name Patanol among others, is an antihistamine medication used to decrease the symptoms of

allergic conjunctivitis Allergic conjunctivitis (AC) is Allergic Inflammation, inflammation of the conjunctiva (the membrane covering the white part of the eye) due to allergy. Although allergens differ among patients, the most common cause is hay fever. Symptoms consist ...

and

allergic rhinitis Allergic rhinitis, of which the seasonal type is called hay fever, is a type of inflammation in the nose that occurs when the immune system overreacts to allergens in the air. It is classified as a type I hypersensitivity reaction. Signs a ...

(hay fever). It is used as eye drops or as a

nasal spray Nasal sprays are used to deliver medications Route of administration#Local, locally in the nasal cavities or systemic administration, systemically. They are used locally for conditions such as nasal congestion and allergic rhinitis. In some sit ...

. The eye drops generally result in an improvement within half an hour. Common side effects include headache, sore throat, eye discomfort, or changes in perception of taste. More significant side effects may include sleepiness. It is unclear if use during

pregnancy Pregnancy is the time during which one or more offspring gestation, gestates inside a woman's uterus. A multiple birth, multiple pregnancy involves more than one offspring, such as with twins. Conception (biology), Conception usually occurs ...

breastfeeding Breastfeeding, also known as nursing, is the process where breast milk is fed to a child. Infants may suck the milk directly from the breast, or milk may be extracted with a Breast pump, pump and then fed to the infant. The World Health Orga ...

is safe. It is an

antihistamine Antihistamines are drugs which treat allergic rhinitis, common cold, influenza, and other allergies. Typically, people take antihistamines as an inexpensive, generic (not patented) drug that can be bought without a prescription and provides ...

and

mast cell stabilizer Mast cell stabilizers are medications used to prevent or treat certain allergic disorders. They block mast cell degranulation, stabilizing the cell and thereby preventing the release of histamine and related mediators. One suspected pharmacody ...

. Olopatadine was patented in 1986 and came into medical use in 1997. It is available as a

generic medication A generic drug is a pharmaceutical drug that contains the same chemical substance as a drug that was originally protected by chemical patents. Generic drugs are allowed for sale after the patents on the original drugs expire. Because the active ch ...

. In 2022, it was the 250th most commonly prescribed medication in the United States, with more than 1million prescriptions.

Medical uses

Olopatadine is an active ingredient in eye drops designed to alleviate

, a condition characterized by itchy, red, and watery eyes. It is intended to serve as a superior alternative to eye drops that contain

corticosteroid Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are invo ...

s. By utilizing olopatadine, the goal is to minimize the side effects associated with corticosteroids. These side effects include elevated

intraocular pressure Intraocular pressure (IOP) is the fluid pressure inside the eye. Tonometry is the method eye care professionals use to determine this. IOP is an important aspect in the evaluation of patients at risk of glaucoma. Most tonometers are calibrated t ...

, which can lead to

glaucoma Glaucoma is a group of eye diseases that can lead to damage of the optic nerve. The optic nerve transmits visual information from the eye to the brain. Glaucoma may cause vision loss if left untreated. It has been called the "silent thief of ...

, 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 and/or stinging, blurred vision, dry eyes, foreign body sensation, hyperemia, keratitis, eyelid

edema Edema (American English), also spelled oedema (British English), and also known as fluid retention, swelling, dropsy and hydropsy, is the build-up of fluid in the body's tissue (biology), tissue. Most commonly, the legs or arms are affected. S ...

pruritus An itch (also known as pruritus) is a sensation that causes a strong desire or reflex to scratch. Itches have resisted many attempts to be classified as any one type of sensory experience. Itches have many similarities to pain, and while both ...

asthenia Weakness is a symptom of many different medical conditions. The causes are many and can be divided into conditions that have true or perceived muscle weakness. True muscle weakness is a primary symptom of a variety of skeletal muscle diseases, ...

, sore throat (

pharyngitis Pharyngitis is inflammation of the back of the throat, known as the pharynx. It typically results in a sore throat and fever. Other symptoms may include a runny nose, cough, headache, difficulty swallowing, swollen lymph nodes, and a hoarse vo ...

rhinitis Rhinitis, also known as coryza, is irritation and inflammation of the mucous membrane inside the nose. Common symptoms are a stuffy nose, runny nose, sneezing, and post-nasal drip. The inflammation is caused by viruses, bacteria, irritant ...

sinusitis Sinusitis, also known as rhinosinusitis, is an inflammation of the mucous membranes that line the sinuses resulting in symptoms that may include production of thick nasal mucus, nasal congestion, facial congestion, facial pain, facial pressure ...

, 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

Pharmacology

Pharmacodynamics

Olopatadine acts as a selective

antagonist An antagonist is a character in a story who is presented as the main enemy or rival of the protagonist and is often depicted as a villain.histamine Histamine is an organic nitrogenous compound involved in local immune responses communication, as well as regulating physiological functions in the gut and acting as a neurotransmitter for the brain, spinal cord, and uterus. Discovered in 19 ...

H₁ 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. In the United States, Pataday Twice Daily Relief was first approved by the FDA in 1996, under the name Patanol as a prescription drug and was indicated for the treatment of the signs and symptoms of allergic conjunctivitis (referring to ocular redness and itching due to allergies). Pataday – now Pataday Once Daily Relief – was first approved by the FDA in 2004, as a prescription drug and was indicated for the treatment of ocular itching associated with allergic conjunctivitis. These drugs are mast cell stabilizers, which work by preventing the release of histamine and therefore prevent or control allergic disorders. In February 2020, Pataday Twice Daily Relief and Pataday Once Daily Relief were switched to be

over-the-counter drug Over-the-counter (OTC) drugs are medicines sold directly to a consumer without a requirement for a prescription from a healthcare professional, as opposed to prescription drugs, which may be supplied only to consumers possessing a valid pres ...

s in the United States when the FDA granted the approvals of the nonprescription products to

Alcon Alcon Inc. () is a Swiss-American pharmaceutical and medical device company specializing in eye care products. It has a paper headquarters in Geneva, Switzerland but its operational headquarters are in Fort Worth, Texas, United States, where it ...

Society and culture

Brand names

Brand names include Pallada, Pazeo, Pataday, Patanol S, Patanol, Opatanol, Olopat, Patanase. It is also available as an oral tablet in Japan under the tradename Allelock, manufactured by Kyowa Hakko Kogyo.

References

External links

* {{Authority control Phenylacetic acids Drugs developed by Alcon Dibenzoxepins Dimethylamino compounds H1 receptor antagonists Mast cell stabilizers Muscarinic antagonists Drugs developed by Novartis Wikipedia medicine articles ready to translate