Which solution is appropriate for preparing intermittent intravenous phenytoin infusion?

The correct choice for preparing an intermittent intravenous phenytoin infusion is 0.9% sodium chloride. Phenytoin, an anticonvulsant medication, can be sensitive to various solutions due to stability and compatibility issues. The use of 0.9% sodium chloride is specifically recommended as it is isotonic, which helps to maintain the stability of phenytoin during infusion. Additionally, phenytoin can precipitate when mixed with dextrose-containing solutions because it may affect the solubility of the drug, leading to complications such as embolism if precipitate forms in the bloodstream.

Lactated Ringer's solution is also not appropriate for phenytoin infusions, as the calcium present in the solution can further destabilize phenytoin, resulting in potential loss of efficacy or adverse reactions. While 5% dextrose in normal saline may seem like a potential option, the presence of dextrose can similarly interfere with the drug's stability, which is why this choice is not recommended either.

Using 0.9% sodium chloride ensures that phenytoin remains soluble throughout the infusion, optimizing both its delivery and therapeutic effect for patients requiring anticonvulsant treatment.