Name a monoclonal antibody with infusion reaction risk and a management step.

• A. Rituximab; premedicate with acetaminophen and diphenhydramine; monitor during infusion; slow or pause if reaction.
• B. Bevacizumab; premedicate with antibiotics; monitor during infusion.
• C. Trastuzumab; no premedication; watch only at end.
• D. Pembrolizumab; double the dose if reaction.

Answer: (A)

Infusion reactions are a known risk with certain monoclonal antibodies, especially during the first exposure when the body’s immune system may respond vigorously to the new antibody. Rituximab is a classic example where this risk is significant. A standard way to reduce that risk is to give premedication with acetaminophen and a histamine-1 blocker like diphenhydramine before starting the infusion, and to monitor the patient closely during the infusion. If a reaction occurs, the infusion should be slowed or paused and treated according to protocol, with cautious resumption if symptoms improve. This combination of premedication, vigilant monitoring, and the option to adjust the infusion rate directly addresses the most common infusion-reaction scenario.

The other options describe inappropriate or incomplete management for this context, such as using antibiotics as premedication, omitting premedication on a drug where reactions are common, or attempting an inappropriate dose adjustment like doubling the dose in response to a reaction.