Pataday belongs to the antihistamines group of drugs and works by blocking histamine release from certain body cells. Pataday is used in the treatment of itching associated with eye allergies. Pataday relieves the symptoms and signs of allergic conjunctivitis (an allergic reaction that affects the eyes), such as swelling of the eye surface, red eyes, and itchy eyes. Pataday blocks histamine, which is released by the body during an allergic reaction. Pataday is a prescription drug indicated for the treatment of the symptoms of allergic pink eye. Pataday is classified under a class of medications known as antihistamines. Pataday works by inhibiting the activities of histamine, a natural substance that causes irritation and inflammation associated with pink eye. Pataday is available as a solution that is instilled in the eye. Pataday is typically used twice a day at an interval of six to eight hours. Use Pataday regularly to treat your condition. Remove contact lenses before instilling Pataday in the eye. Also, check if the dropper tip is chipped or cracked to avoid contamination.