Hay-Crom (sodium cromoglicate)
Hay-Crom 2% w/v Eye Drops contain a medicine called sodium cromoglicate. This belongs to a group of medicines called anti-allergics.
It works by stopping the release of the natural substances in your eyes that can lead to an allergic reaction. Signs of an allergic reaction include itchy, watery, red or inflamed eyes and puffy eyelids.
Hay-Crom is used for the prevention and treatment of eye allergies. These allergies can happen:
- At any time of the year and is called ‘perennial allergic conjunctivitis’
- In different seasons of the year caused by different pollens. This is called ‘seasonal allergic conjunctivitis’ or hay fever
How do Hay-Crom eye drops work?
- Hay-Crom allergy eye drops contain the active ingredient sodium cromoglicate, which is a type of medicine that reduces allergic responses. It is thought to work by 'stabilising' immune cells called mast cells.
- Mast cells are an important part of the immune system. They become sensitised when they are exposed to foreign particles or allergens, for example pollen or pet fur. When this happens, the mast cells release substances that include histamine, and these cause inflammation as part of the body's immune response to fight the foreign substance. Inflammation in the eyes causes the typical symptoms of an eye allergy - redness, itching, puffiness and a watery discharge.
- By stabilising the mast cells, sodium cromoglicate is thought to prevent the substances that cause the inflammation, eg histamine, from being released when the cells encounter an allergen. This helps prevent the allergic response and reduce the symptoms of the allergy.
How do I use Hay-Crom eye drops?
- Wash your hands before using the eye drops.
- One or two drops should be put into each eye four times a day, or as directed by your doctor.
- Take care to not touch the tip of the dropper to any surface, or to your eye, in order to avoid contaminating the medicine.
- It may take a few days for your symptoms to be fully relieved by these eye drops, so if possible it's best to start using them a few days before you're exposed to the allergen. You can use the drops every day to control your symptoms for as long as you're exposed to the allergen, for example throughout the pollen season. However, if you need to use the drops continuously for longer than three months you should get advice from your doctor or pharmacist.
- These eye drops should be disposed of four weeks after the bottle is first opened. This is because after this time they could be contaminated with dirt or germs that could cause eye infections. Write the date of opening on the bottle so you know when to throw them away. Dispose of them carefully, preferably by returning them to your pharmacy.
Who shouldn't use Hay-Crom eye drops?
- People who wear contact lenses. Hay-Crom allergy eye drops contain the preservative benzalkonium chloride, which can be absorbed by soft contact lenses and cause eye irritation. You should not wear contact lenses while you are using these eye drops.
- People with known sensitivity or allergy to any of the ingredients. If you feel you have experienced an allergic reaction, stop using these eye drops and get advice from your doctor or pharmacist.
Can I use Hay-Crom allergy eye drops while pregnant or breastfeeding?
- These eye drops are not known to be harmful if used during pregnancy or breastfeeding. However, as with all medicines, they should only be used if essential and recommended by your doctor.
What are the possible side effects?
- Temporary burning or stinging after putting the drops into the eyes.
- Eye drops may cause your vision to blur temporarily after you have put them in your eye. Do not drive or operate machinery until this has worn off.
- If you want any more information about the possible side effects of these eye drops you should read the leaflet that comes with the medicine or talk to your doctor or pharmacist.
Can I use Hay-Crom eye drops with other medicines?
- If you're already using any other medicines, including those bought without a prescription and herbal medicines, it's best to check with your pharmacist before using these eye drops as well, to make sure that the combination is safe and appropriate.
- If you need to use more than one type of eye drop you should administer them at least five minutes apart, to avoid the second drop washing away the first. Use eye gels or ointments last.
- Sodium cromoglicate eye drops are not known to affect other medicines. It's fine to use them with other types of hay fever treatment, such as antihistamines or nasal sprays.