Mast cell stabilizers

Mast cell stabilizers block the release of chemicals in the immune system that contribute to allergic reactions. These drugs are generally safe but usually need to be used for several days to produce the full effect. They're usually used when antihistamines are not working or not well-tolerated.

Nasal spray

Over-the-counter nasal sprays include cromolyn (Nasalcrom).

Eyedrops

Prescription eyedrops include the following:

• Cromolyn (Crolom)
• Lodoxamide (Alomide)
• Nedocromil (Alocril)