Which drug class counteracts the effects of histamines?

The drug class that counteracts the effects of histamines is antihistamines. These medications work by blocking the action of histamines, which are chemicals released during allergic reactions and can cause symptoms such as itching, sneezing, runny nose, and hives. By binding to histamine receptors, antihistamines prevent histamines from exerting their effects on the body, thereby alleviating allergy symptoms. This functionality is pivotal for managing conditions like allergic rhinitis or hay fever.

In contrast, the other classes of drugs listed serve different purposes. Antibiotics are used to treat bacterial infections, anticoagulants help prevent blood clots, and antivirals target viral infections. Each of these classes operates through mechanisms unrelated to the histamine pathway, reinforcing why antihistamines are specifically the correct response to the question regarding counteracting the effects of histamines.