A nurse is preparing to administer phenytoin IV to a client who had a tonic-clonic seizure. Which of the following actions should the nurse plan to take?

Phenytoin is a potent antiepileptic that requires extreme caution during intravenous administration due to its high alkalinity and potential for precipitation. It is incompatible with most intravenous solutions and must be delivered through a large-bore catheter to prevent extravasation and tissue necrosis. Close cardiovascular monitoring is mandatory during infusion to detect potential arrhythmias or severe hypotension. Rationale: A. Injecting sterile water after administration is not the standard protocol; instead, the line must be flushed with 0.9% sodium chloride. Phenytoin is highly unstable and will precipitate if it comes into contact with many other fluids. Using 0.9% sodium chloride ensures the vein is cleared of the medication without causing the formation of dangerous micro-crystals in the IV tubing. B. Administering phenytoin with 5% dextrose in water (D5W) is strictly contraindicated because the medication will immediately precipitate into a solid form. Phenytoin is only compatible with 0.9% sodium chloride, and any contact with glucose-containing solutions leads to crystallization. Such precipitates can cause emboli or severe vein irritation, compromising the safety of the intravenous access site. C. Discarding the medication if it appears cloudy is a critical safety action because cloudiness indicates that the phenytoin has precipitated. Intravenous phenytoin should be a clear, colorless solution; any presence of crystals or opaqueness means the drug is no longer safe for infusion. Injecting a precipitated solution can cause catastrophic vascular damage or pulmonary embolism in the client. D. Administering the medication at a rate of 100 mg/min is dangerously fast and exceeds the maximum recommended safety limit. To prevent severe hypotension and cardiac arrhythmias, the infusion rate must not exceed 50 mg/min for adults. Rapid administration can lead to cardiovascular collapse, making slow, controlled delivery and continuous heart rate monitoring an essential nursing priority.