The CEREBYX (fosphenytoin) monograph
found in Intravenous Medications, by Gahart and Nazareno (St.
Louis. Mosby 1999), incorrectly expresses the phenytoin equivalent
amount in the manufacturer's vial as 75 mg PE/mL instead of
50 mg PE/mL. Also, the rate of administration for elderly
and pediatric patients is ambiguously stated. For example,
it states that the rate should not exceed "37.5 mg PE/minute
(equivalent to 25 mg/min of phenytoin)." Since both are expressed
in terms of phenytoin equivalents, it is impossible to know
which figure is actually the phenytoin equivalent amount that
should be infused. This monograph needs to be corrected immediately
wherever the book may be in use within your institution. This
is one of many examples of confusion caused by the unconventional
"PE" method of dosing fosphenytoin.
