Which antihistamine is administered intravenously (V) when a blood transfusion reaction causes pruritus?

A. Fexofenadine: Fexofenadine is a second-generation antihistamine typically administered orally. It is non-sedating and not available in an intravenous form, so it is not suitable for immediate treatment of pruritus during an acute blood transfusion reaction. B. Loratadine: Loratadine is also a second-generation oral antihistamine. It does not have an intravenous formulation and its onset is slower, making it ineffective for rapid symptom relief in acute transfusion reactions. C. Cetirizine: Cetirizine is a second-generation antihistamine available orally. Although it is effective for allergic reactions, it does not have an IV form for rapid intervention during a transfusion-related pruritus episode. D. Diphenhydramine: Diphenhydramine is a first-generation antihistamine that can be administered intravenously for rapid relief of pruritus during acute allergic reactions, including blood transfusion reactions. Its IV form allows immediate onset of action, which is critical in managing these acute symptoms.