What is the role of antihistamines in the treatment of upper respiratory disorders?

• A. They reduce fever and pain from sinus infections
• B. They block histamine effects and reduce allergy symptoms
• C. They improve sinus drainage and reduce congestion
• D. They directly treat bacterial infections

Answer: (B)

Antihistamines work by blocking histamine effects at the H1 receptor, which are central to allergic symptoms in the upper airway. When an allergen triggers mast cells, histamine is released and causes sneezing, itching, runny nose, and watery eyes through increased secretions and nerve stimulation. By antagonizing the histamine receptor, antihistamines prevent these actions, leading to relief of those allergy symptoms.

They do not reduce fever or pain, which are managed with analgesics or antipyretics. They also don’t directly improve sinus drainage or congestion in the sense of clearing blockages, though drying of secretions can help with rhinorrhea. And they don’t treat bacterial infections, which require antibiotics. So the role of antihistamines is specifically to block histamine effects and reduce allergy-related symptoms.