What is the primary function of an antipruritic?

An antipruritic is specifically designed to relieve itching, making it the most suitable choice for this question. The term "antipruritic" itself stems from the root "pruritus," which is the medical term for itching. These substances can work by blocking nerve signals that transmit the sensation of itch or by reducing the skin's inflammatory response, thereby providing much-needed relief for conditions that cause intense itching, such as eczema, allergic reactions, or insect bites.

The primary function of antipruritics distinguishes them from other types of medications. For example, medications focused on preventing inflammation address different symptoms and mechanisms than those specifically target itching. Similarly, lowering blood pressure pertains to cardiovascular functions, and inducing sleep relates to managing insomnia or sleep disorders, which are separate health concerns that do not overlap with the function of an antipruritic. Therefore, the role of relieving itching is uniquely characteristic of antipruritics, affirming that this is indeed the correct answer.