Final answer:
The nurse should assess the child's blood pressure before administering losartan to a school-aged child with chronic renal failure. This ensures the child's safety as losartan directly affects blood pressure.
Step-by-step explanation:
Prior to administering losartan to a school-aged child with chronic renal failure, the nurse should assess the child's blood pressure. Losartan is a medication that affects blood pressure and could lower it, so it's crucial to ensure the child's blood pressure is not too low before giving the drug. The action of checking blood pressure addresses safety concerns related to the primary effect of losartan. Additionally, due to the potential for drugs to cause side effects especially in patients with organ dysfunction like renal failure, close monitoring is necessary.
Other actions, such as ensuring vaccinations are up to date, obtaining a urine sample, and verifying allergies, while important, are not as immediately pertinent to the administration of losartan as blood pressure assessment. When considering dosage and route of administration for any medication, healthcare providers must consider the patient's age, mass, and any organ dysfunction that might affect drug metabolism or clearance. Since the child has chronic renal failure, the nurse should also be mindful of potential altered drug clearance.