Which IV solution should not be used with Dilantin during IV administration?

• A. Normal Saline
• B. Lactated Ringer's
• C. Dextrose-Containing Solutions
• D. Sterile Water For Injection

Answer: (C)

IV administration of phenytoin must use a compatible diluent because the drug is not soluble in solutions that contain dextrose. Mixing phenytoin with dextrose-containing fluids causes precipitation, which can clog the IV line, deliver an ineffective dose, or lead to particulate matter entering the circulation. For this reason, dextrose-containing solutions should not be used to administer Dilantin IV. Normal saline is the typical diluent, and phenytoin is often given through a dedicated IV line with appropriate infusion rate and monitoring. (Calcium-containing solutions like lactated Ringer’s have their own concerns with certain drugs, but the primary test point here is the incompatibility with dextrose.)