Optilast eye drops contain the active ingredient azelastine 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 pollen, pet fur, dust mites), 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 (seasonal allergic conjunctivitis), eg caused by flower pollen or grasses, histamine causes inflammation of the eyes, making them red, itchy and watery.
Azelastine 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.
This medicine should not be used if you are allergic to one or 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.
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.
If you are pregnant or breastfeeding and do use these eye drops (only on your doctor's advice), you can minimise the amount of medicine that is absorbed into your bloodstream by pressing on your tear duct while putting in the drops, and for a few minutes after. The tear duct is at the corner of the eye closest to your nose.
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.
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.
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.