Which drug is known to crystallize when administered intravenously with D5S?

Phenytoin is known to crystallize when administered intravenously with D5S (5% dextrose in saline). This phenomenon occurs because phenytoin is poorly soluble in certain concentrations, particularly in dextrose solutions. When the drug is mixed with D5S, the concentration can reach a threshold that causes phenytoin to crystallize, potentially leading to complications such as phlebitis or emboli if the crystalline particles enter the bloodstream.

In clinical practice, this characteristic of phenytoin necessitates the use of other diluents, such as normal saline (0.9% sodium chloride), for intravenous administration to prevent crystallization and ensure a safe and effective delivery of the medication to the patient. Understanding the solubility and compatibility of IV medications is crucial in the ICU setting to avoid adverse events.