The charge nurse asks the practical nurse (PN) to administer diphenhydramine 25 mg IM to a client prior to infusing a blood transfusion. Which explanation should the PN offer the client about the purpose of this drug?

Choice A reason: Pupils equal and reactive to light assess neurological status, not bronchodilator effectiveness. Bronchodilators, like albuterol, relax airway smooth muscles, improving breathing in emphysema. Pupil response is unrelated to respiratory function, making this choice irrelevant for evaluating the drug’s impact.

Choice B reason: Heart rate of 106 beats/minute may reflect a bronchodilator side effect, as beta-agonists stimulate cardiac beta receptors, causing tachycardia. However, it does not measure effectiveness, which is assessed by improved airway function, like respiratory rate, making this choice incorrect.

Choice C reason: Respiratory rate of 22 breaths/minute indicates bronchodilator effectiveness, as these drugs dilate airways, reducing work of breathing in emphysema. A normalized rate suggests improved airflow and oxygenation, directly reflecting the drug’s therapeutic action on bronchial smooth muscle relaxation.

Choice D reason: Urine output of 40 mL/hour monitors renal function, not bronchodilator efficacy. Bronchodilators target airway dilation, not fluid balance. This finding is unrelated to emphysema treatment or the drug’s respiratory effects, making it irrelevant for assessing medication effectiveness.

Choice A reason: Antilipidemic medications, like statins, lower serum cholesterol by inhibiting HMG-CoA reductase, reducing low-density lipoprotein (LDL) production. Monitoring cholesterol levels, particularly LDL, directly assesses the drug’s effectiveness in reducing cardiovascular risk, as elevated cholesterol is the primary target of therapy.

Choice B reason: Hemoglobin A1C reflects blood glucose control, relevant for diabetes management, not lipid-lowering therapy. Antilipidemics target cholesterol, not glucose metabolism. This value is unrelated to the drug’s mechanism, making it irrelevant for assessing antilipidemic efficacy.

Choice C reason: INR monitors anticoagulation, relevant for drugs like warfarin, not antilipidemics. Cholesterol-lowering drugs do not affect clotting pathways. Monitoring INR is unnecessary, as it does not reflect the therapeutic goal of reducing lipid levels, making this choice incorrect.

Choice D reason: Platelet count assesses bleeding risk or bone marrow function, not lipid levels. Antilipidemics do not significantly affect platelets. Monitoring cholesterol is the direct measure of efficacy, as platelets are unrelated to the drug’s cholesterol-lowering mechanism, making this choice irrelevant.