Other forms: antihistamines
An antihistamine is a type of drug you might take if you suffer from allergies. If your friend's cat makes your throat itch and your eyes swell, you should probably take an antihistamine.
Antihistamines work by suppressing the effects of histamine in your body — this is substance released by your cells when you're exposed to allergens, or things you're allergic to. It's histamine that makes you sneeze or get itchy hives, and it's antihistamine that soothes this reaction. This scientific word comes from anti-, "against," histidine, an amino acid, and amine, a certain kind of organic compound.