Olopatadine hydrochloride is an antihistamine

Antihistamine

An H1 antagonist is a histamine antagonist of the H1 receptor that serves to reduce or eliminate effects mediated by histamine, an endogenous chemical mediator released during allergic reactions...

 (as well as anticholinergic

Anticholinergic

An anticholinergic agent is a substance that blocks the neurotransmitter acetylcholine in the central and the peripheral nervous system. An example of an anticholinergic is dicycloverine, and the classic example is atropine....

) and mast cell

Mast cell

A mast cell is a resident cell of several types of tissues and contains many granules rich in histamine and heparin...

 stabilizer, sold as a prescription

Prescription drug

A prescription medication is a licensed medicine that is regulated by legislation to require a medical prescription before it can be obtained. The term is used to distinguish it from over-the-counter drugs which can be obtained without a prescription...

 eye drop

Eye drop

Eye drops are saline-containing drops used as a route to administer medication in the eye. Depending on the condition being treated, they may contain steroids, antihistamines, sympathomimetics, beta receptor blockers, parasympathomimetics, parasympatholytics, prostaglandins, non-steroidal...

 (0.2% solution, Pataday (or Patanol S in some countries), manufactured by Alcon

Alcon

Alcon incorporated and with corporate headquarters, in Hünenberg, Switzerland, is a global medical company specializing in eye care products. Alcon's U.S. headquarters is located in Fort Worth, Texas...

). It is used to treat itching associated with allergic conjunctivitis

Conjunctivitis

Conjunctivitis refers to inflammation of the conjunctiva...

 (eye allergies

Allergy

An Allergy is a hypersensitivity disorder of the immune system. Allergic reactions occur when a person's immune system reacts to normally harmless substances in the environment. A substance that causes a reaction is called an allergen. These reactions are acquired, predictable, and rapid...

). Olopatadine hydrochloride 0.1% is sold as Patanol (or Opatanol in some countries). A nasal spray

Nasal spray

Nasal sprays come in a variety of forms. Medicated such as Astelin, Afrin and Nasonex and natural such as Sinusoothe and Sterimar. Although delivery methods vary, most nasal sprays function by instilling a fine mist into the nostril by action of a hand-operated pump mechanism.-Antihistamine nasal...

 formulation is sold as Patanase, which was approved by the FDA on April 15, 2008. It is also available as an oral tablet in Japan under the tradename Allelock, manufactured by Kyowa Hakko Kogyo.

It should not be used to treat irritation caused by contact lenses. The usual dose for Patanol is 1 drop in each affected eye 2 times per day, with 6 to 8 hours between doses.

Its side effects

Adverse drug reaction

An adverse drug reaction is an expression that describes harm associated with the use of given medications at a normal dosage. ADRs may occur following a single dose or prolonged administration of a drug or result from the combination of two or more drugs...

 may include headache

Headache

A headache or cephalalgia is pain anywhere in the region of the head or neck. It can be a symptom of a number of different conditions of the head and neck. The brain tissue itself is not sensitive to pain because it lacks pain receptors. Rather, the pain is caused by disturbance of the...

s (7% of occurrence) burning and stinging (5%), dry eye, foreign body

Foreign body

A foreign body is any object originating outside the body. In machinery, it can mean any unwanted intruding object.Most references to foreign bodies involve propulsion through natural orifices into hollow organs....

 sensation, hyperemia, keratitis

Keratitis

Keratitis is a condition in which the eye's cornea, the front part of the eye, becomes inflamed. The condition is often marked by moderate to intense pain and usually involves impaired eyesight.-Types:...

, lid

Eyelid

An eyelid is a thin fold of skin that covers and protects an eye. With the exception of the prepuce and the labia minora, it has the thinnest skin of the whole body. The levator palpebrae superioris muscle retracts the eyelid to "open" the eye. This can be either voluntarily or involuntarily...

 edema

Edema

Edema or oedema ; both words from the Greek , oídēma "swelling"), formerly known as dropsy or hydropsy, is an abnormal accumulation of fluid beneath the skin or in one or more cavities of the body that produces swelling...

, pruritus, asthenia, cold syndrome, pharyngitis

Pharyngitis

Pharyngitis is an inflammation of the throat or pharynx. In most cases it is quite painful, and is the most common cause of a sore throat.Like many types of inflammation, pharyngitis can be acute – characterized by a rapid onset and typically a relatively short course – or chronic....

, rhinitis

Rhinitis

Rhinitis , commonly known as a stuffy nose, is the medical term describing irritation and inflammation of some internal areas of the nose. The primary symptom of rhinitis is nasal dripping. It is caused by chronic or acute inflammation of the mucous membrane of the nose due to viruses, bacteria or...

, sinusitis

Sinusitis

Sinusitis is inflammation of the paranasal sinuses, which may be due to infection, allergy, or autoimmune issues. Most cases are due to a viral infection and resolve over the course of 10 days...

, and taste perversion.

Olopatadine was developed by Kyowa Hakko Kogyo.

External links

• Pataday website
• Patanase website
• Olopatadine Ophthalmic via MedlinePlus
  MedlinePlus
  MedlinePlus is a free Web site that provides consumer health information for patients, families, and Health care providers. The site brings together information from the United States National Library of Medicine, the National Institutes of Health , other U.S. government agencies, and...