Most medications fall into the antihistamine category, either topical or oral.
Both work to block the release of histamine, which causes many of the symptoms. You can find out more about your body's reaction to allergens here. Orally ingested antihistamines may partially relieve ocular symptoms. They can be a convenient way to obtain relief although it can often take an hour or more before they begin to work. Some oral antihistamines can produce unwanted side-effects such as drowsiness, irritability and dryness.