Which infusion is titrated up to achieve the prescribed dose?

• A. Gemtuzumab
• B. Rituximab
• C. Topotecan
• D. Imatinib

Answer: (B)

Infusion rate titration is used to reduce infusion-related reactions when giving IV therapies, especially monoclonal antibodies. The idea is to start the infusion at a slow rate and carefully increase the rate step by step, as long as the patient tolerates it, until the full prescribed dose is delivered.

Rituximab is given with this approach on the first infusion: you begin at a low rate and gradually ramp up to the full dose rate if no significant reactions occur. The actual dose is fixed based on body size or surface area, but the rate at which that dose is infused is increased in increments to improve safety. Premedication with acetaminophen and an antihistamine (and sometimes steroids) is commonly used to further reduce infusion reactions.

The other drugs listed are not typically infused with a rate-titration strategy to reach the prescribed dose: they are given as fixed doses over a set infusion time or, in the case of the oral drug, as a daily dose taken by mouth, so there isn’t a ramp-up of the infusion rate to reach the prescribed amount.