What should a nurse do before administering phenytoin suspension to a child?

Before administering phenytoin suspension to a child, it is essential to shake the container vigorously. Phenytoin suspension can separate over time, and the active ingredients may not be evenly distributed throughout the liquid. Shaking the container ensures that the medication is uniformly mixed, allowing for accurate dosing and effective treatment. This step is crucial for achieving the intended therapeutic effect, as any sediment at the bottom may indicate an improper concentration of the drug, which could lead to ineffective treatment or increased risk of side effects.

In this context, administering the medication cold is not advisable, as it may affect the medication's consistency, and using a filter is unnecessary for oral suspensions, as they typically do not require filtration. Measuring the medication in solid form is also inappropriate, as phenytoin is provided as a suspension for a reason: to allow for easier administration and dosing in pediatric patients. Thus, the correct action is to vigorously shake the phenytoin suspension before giving it to ensure proper mixing and delivery of the medication.