Ketotifen
Ketotifen fumarate (ZaditorĀ®) is an H1-antihistamine available in two forms. In its opthalmic form, it is used to treat allergic conjunctivitis, or the itchy red eyes caused by allergies. In its oral form, it is used to prevent asthma attacks. Side effects include drowsiness, weight gain, dry mouth, irritability, and increased nosebleeds.