Sodium cromoglicate (Rynacrom nasal spray)

How does it work?

Rynacrom nasal spray contains the active ingredient sodium cromoglicate, which is a type of medicine used to prevent the symptoms of allergies. Sodium cromoglicate nasal spray is used to prevent the symptoms of nasal allergies such as hay fever.

Sodium cromoglicate works by reducing allergic responses. It is not fully understood how it does this, but 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 dust mites. 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 of the nasal lining causes the typical symptoms of a nasal allergy - blocked or runny nose, itching and sneezing.

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.

Rynacrom nasal spray is used to prevent a blocked or runny nose, itching and sneezing caused by nasal allergies (allergic rhinitis) such as hay fever. It works best if you start using it a couple of weeks before you expect to be exposed to the allergen. You should use it regularly as long as you are around the allergen, even when you don't have symptoms.

What is it used for?

  • Preventing symptoms of nasal allergies (allergic rhinitis), eg caused by hay fever, pet allergies or dust mite allergies.

This nasal spray is suitable for all age groups.

How do I use it?

  • Before using Rynacrom spray for the first time you should prime it. Hold the bottle upright and pump it at least three times into the air until an even spray emerges.
  • You should preferably start using this nasal spray a couple of weeks before you expect to be exposed to the allergen, eg before the start of the pollen season. You should keep then using it regularly every day for as long as you are still exposed to the thing you are allergic to.
  • One spray should be used in each nostril two to four times a day, or as directed by your doctor. Try to space your doses evenly.
  • Follow this link for instructions on how to use your nasal spray.
  • If you forget to use a dose of the spray use it as soon as you remember, unless it is nearly time for your next dose. In this case just leave out the missed dose and use one spray in each nostril for your next dose as usual. Don't use a double spray to make up for a missed dose.


  • This medicine is for use in the nose only. It should not be taken by mouth. Avoid getting the spray in the eyes.
  • This medicine contains benzalkonium chloride, which may rarely cause difficulty breathing, wheezing or tightness in the chest (bronchospasm). Stop using this nasal spray and consult your doctor if you experience any of these symptoms after using it.

Not to be used in

  • Known sensitivity or allergy to any ingredients.

This medicine should not be used if you are sensitive or 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.

  • This medicine is not known to be harmful if used during pregnancy. However, as with all medicines, pregnant women should seek medical advice from their doctor or pharmacist before using this medicine.
  • It is not known if this medicine passes into breast milk, however it is not known to have any harmful effects when used by breastfeeding mothers. As with all medicines, you should seek medical advice from your doctor or pharmacist before using this medicine if you are breastfeeding.

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.

  • Irritation of the nose.
  • Wheezing or chest tightness (rare).

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?

This medicine is not known to affect any other medicines. However, if you are already using any other medicines, including those bought without a prescription and herbal medicines, it is important to check with your pharmacist before using this medicine as well, to make sure that the combination is safe and appropriate for you.

Other medicines containing the same active ingredient

  • Allercrom eye drops.
  • Boots hayfever relief eye drops.
  • Catacrom eye drops.
  • Murine hayfever relief eye drops.
  • Opticrom allergy eye drops.
  • Opticrom aqueous eye drops.
  • Opticrom hayfever eye drops.
  • Optrex allergy eye drops.
  • Vividrin eye drops.
  • Vividrin nasal spray.