Opatanol is used to treat the eye symptoms of seasonal allergic conjunctivitis (inflammation of the eyes caused by pollen in patients with hayfever). These include itching, redness and swelling.

What is it used for?

  • Relieving the eye symptoms of hay fever (seasonal allergic conjunctivitis) in adults and children aged three years and older.

How does it work?

  • Opatanol eye drops contain the active ingredient olopatadine hydrochloride, which is a type of medicine called an antihistamine. It works by preventing the actions of histamine.
  • Histamine is a substance produced by the body as part of its defence mechanisms. It is stored in cells called mast cells, in almost all tissues of the body. When the body reacts to a foreign substance (known as an allergen, eg flower or grass pollen), the mast cells stimulated by the allergen release their stores of histamine.
  • The released histamine then binds to its receptors (H-1 receptors), causing a chain reaction that results in allergic symptoms.
It causes an increase in blood flow to the area of the allergy, and the release of other chemicals that add to the allergic response. All this results in the symptoms of an allergic reaction.
  • In eye allergies such as hay fever, eg caused by flower pollen or grasses, histamine causes inflammation of the eyes, making them red, itchy and watery.
  • Olopatadine eye drops work by blocking the histamine receptors in the eyes. This stops it causing inflammation and thus provides relief from the symptoms of the eye allergy.
  • How do I use it?

    • Opatanol eye drops contain the preservative benzalkonium chloride, which can be absorbed by soft contact lenses and cause eye irritation. For this reason if you wear soft contact lenses, you should remove them before putting in these eye drops. Wait at least 15 minutes before putting your lenses back in. However, if possible it is best not to wear your contact lenses at all while you are using these drops.
    • Wash your hands before using the eye drops.
    • One drop should be put into each eye twice a day when needed to relieve symptoms. If necessary you can use these eye drops daily to control your symptoms throughout the pollen season. However, you should not use them for longer than four months.
    • If you forget to use the drops put the missed dose in as soon as you remember, unless it is almost time for your next dose. In this case you should just apply your next dose as usual and miss out the forgotten dose. Don't use a double dose to make up for a forgotten dose.

    Not to be used in

    • Children under three years of age.
    • This medicine should not be used if you are allergic to any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.
    • If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.

    Pregnancy and breastfeeding

    • Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.
    • The safety of this medicine for use during pregnancy has not been established. It should be used with caution during pregnancy, and only if the benefits to the mother outweigh any risks to the developing baby. Seek medical advice from your doctor.
    • It is not known if this medicine passes into breast milk. It is not recommended for women who are breastfeeding. Seek further medical advice from your doctor.

    Side effects

    Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Just because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect.


    • Eye pain or irritation.
    • Dry eyes.
    • Abnormal sensation in the eyes.
    • Headache.
    • Unusual taste.
    • Dryness in the nose.
    • Fatigue.


    • Blurred vision.
    • Discharge from the eye.
    • Eye discomfort or itching.
    • Watery eyes.
    • Red eyes.
    • Sensation of something in the eye.
    • Inflammation of the surface of the eye (keratitis).
    • Staining or other disorders of the cornea.
    • Dislike of light (photophobia).
    • Redness, swelling or itching of the eyelids.
    • Dry skin.
    • Rash.
    • Inflammation of the nasal lining, causing a blocked or runny nose.
    • Dizziness.
    • Reduced sensation.
    • Unknown frequency

    The side effects listed above may not include all of the side effects reported by the medicine's manufacturer.

    For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.

    How can this medicine affect other medicines?

    • If you are using more than one type of eye drop you should administer them at least five minutes apart, to prevent the second drop washing away the first. Use eye gels or ointments last.

    This medicine has not been reported to affect any other medicines.