Antihistaminic is a term commonly used in the medical field to refer to drugs that are used to treat allergies and other conditions caused by the release of histamines in the body. Some synonyms for antihistaminic include histamine blockers, histamine antagonists, and allergy medicines. Other terms that can be used include allergy relief medication, hay fever tablets, and allergy suppressants. These types of medications can be found over-the-counter or by prescription as pills, capsules, liquids, or sprays. They work to alleviate symptoms such as itching, sneezing, and runny nose by blocking the effects of histamine on the body.