Which of the following is NOT a function of antihistamines?

Antihistamines primarily function by blocking the effects of histamine, a substance in the body that is involved in allergic reactions. They are effective in reducing symptoms associated with allergies, such as itching, runny nose, and hives. Specifically, they can reduce itching by acting on the H1 receptors in the body that are responsible for this symptom, making options that involve reducing itching and mitigating allergic reactions correct.

Additionally, antihistamines may also play a role in inhibiting inflammation to some extent, as they can prevent the histamine release that contributes to inflammation during allergic responses.

Inducing urine production is not a known function of antihistamines, which is why this option stands out as not being part of their primary actions. Antihistamines do not have diuretic properties; instead, they focus on blocking histamine’s effects, making the assertion that they help induce urine production incorrect in the context of their intended use.