A client receives a prescription for intravenous (IV) famotidine. Which finding indicates to the practical nurse (PN) the medication is effective?

Choice A reason: Diphenhydramine does not facilitate rapid transfusion. It is an antihistamine used to prevent allergic reactions during transfusions, not to alter infusion speed. Rapid infusion depends on clinical protocols and patient tolerance, not antihistamine effects, making this choice incorrect.

Choice B reason: Diphenhydramine does not inhibit antigen-antibody reactions, which occur in transfusion mismatches. It mitigates histamine-mediated allergic symptoms, like itching or hives, but does not prevent immunological reactions. This choice is incorrect, as it misrepresents the drug’s role in symptom management.

Choice C reason: While diphenhydramine may cause sedation, its primary purpose before transfusion is to prevent allergic reactions, not to promote relaxation. Relaxation is a secondary effect, not the clinical rationale for its use, making this choice less accurate than allergy prevention.

Choice D reason: Diphenhydramine, an antihistamine, minimizes allergic reaction symptoms, such as itching or hives, during blood transfusions by blocking histamine receptors. This premedication reduces the risk of mild transfusion-related allergic responses, ensuring patient comfort and safety, making it the correct explanation.

Choice A reason: Instructing the UAP to bring a breakfast tray ensures nutritional support but is not the highest priority. Regular insulin peaks within 2–4 hours, risking hypoglycemia if not monitored. Observing for hypoglycemic symptoms takes precedence to ensure immediate safety post-administration.

Choice B reason: Observing for pallor, diaphoresis, or fatigue is critical, as these indicate hypoglycemia, a serious risk after regular insulin administration. Insulin lowers blood glucose, and rapid drops can impair brain function or cause seizures. Monitoring for these signs ensures timely intervention, prioritizing client safety.

Choice C reason: Measuring vital signs and oxygen saturation provides general data but is less specific than monitoring for hypoglycemia symptoms. Regular insulin’s rapid action increases hypoglycemic risk, and symptoms like diaphoresis are more direct indicators, making this choice secondary to targeted observation.

Choice D reason: Notifying the charge nurse of the insulin dose is routine but not urgent. The priority is monitoring for hypoglycemia, as regular insulin can cause rapid glucose drops, leading to serious complications. Immediate client observation outweighs administrative tasks in ensuring safety.