Olopatadine

Key points

• Olopatadine is a mast cell stabiliser that blocks the release of histamine and other chemicals responsible for eye itching and redness.
• The drops are not recommended during pregnancy or breastfeeding, as a risk to the baby cannot be excluded.
• The formula contains benzalkonium chloride, which can be absorbed by soft contact lenses and change their colour; remove lenses before applying the drops.

How does Olopatadine work?

Olopatadine blocks histamine, the chemical your body releases when it reacts to an allergen such as pollen or pet dander. It also prevents histamine-induced inflammation in the cells lining the eye. Lab data suggest it may act on mast cells in the conjunctiva to stop the release of further inflammatory chemicals. Together, these actions interrupt the allergic response before itching and swelling take hold.

Because the drops go into the eye rather than being swallowed, very little medicine enters the rest of the body. Plasma levels after topical use are 50 to 200 times lower than after an oral dose, so systemic side effects are uncommon. This places olopatadine in the Allergy Relief range as a targeted, local treatment.

Further reading

• Olopatadine Ophthalmic: MedlinePlus Drug Information
• Olopatadine 1 mg/ml Eye drops, Solution - Summary of Product Characteristics (SmPC) - (emc) | 10890