To minimize adverse reactions during vancomycin administration, the infusion should be completed in at least how many minutes?

• A. 15 minutes
• B. 30 minutes
• C. 60 minutes
• D. 120 minutes

Answer: (C)

The key idea is that vancomycin must be infused slowly to prevent histamine-related reactions, such as red man syndrome. Infusing it too rapidly can trigger flushing, itching, rash, and even hypotension due to a sudden histamine surge. To minimize these adverse effects, the drug should be given over a substantial period—at least one hour. That slow rate lowers peak plasma concentrations and helps avoid the rapid histamine release that leads to the reaction. So, the safest and most effective approach is to complete the infusion in at least one hour. Longer infusion times are acceptable but not necessary for minimizing reactions.