Clinical use of intravenous phenytoin sodium infusions

The safety of administering phenytoin sodium by intermittent intravenous infusion was evaluated. Twenty-eight adult patients in a neurosurgical intensive-care unit were studied; most patients had head trauma. Ninety-three doses of phenytoin sodium 300 mg in 0.9% sodium chloride injection 50 ml were administered according to hospital-approved guidelines, which included administration over 30-60 minutes, initiation of infusion within one hour of solution preparation, and use of a 5-microns inline filter. All patients were monitored for adverse reactions and were on continuous ECG monitoring. Analysis of clinical data before and immediately after phenytoin infusions showed no statistically significant change in blood pressure and a small but significant drop in mean heart rate. There were no cases of hypotension, arrhythmias, bradycardia, or phlebitis. Single occurrences of hypertension, nystagmus, and pain at the i.v. site were noted. It is concluded that careful infusion of phenytoin sodium in 0.9% sodium chloride injection is safe. The use of approved written guidelines to govern important factors of preparation and administration are recommended.