What is a common characteristic of antihistamines?

Antihistamines are primarily known for their role in blocking the action of histamine, a substance in the body that is involved in allergic reactions. When histamine is released during an allergic response, it can cause symptoms such as sneezing, itching, and runny nose. Antihistamines work by binding to histamine receptors, thereby preventing histamine from exerting its effects on the body. This characteristic makes them effective in treating allergies and allergic reactions.

The other options do not align with the primary function of antihistamines. For instance, while some medications may treat infections, antihistamines do not have this property. Additionally, antihistamines do not have a direct role in lowering blood pressure or promoting blood clotting. Understanding the specific mechanism of action of antihistamines, particularly their ability to block histamine, is crucial in recognizing their therapeutic uses in allergy management.