Phenytoin is used singly or in combination with other anticonvulsants to treat grand mal epilepsy. Monitoring the serum levels of antiepileptic drugs has increased the efficiency and safety of drug therapy in epilepsy. It facilitates individualization of dosage regimen, reveals irregular drug intake and identifies the responsible agent in intoxicated patients on multiple drug therapy. Free phenytoin is especially useful in patients with altered phenytoin binding to protein, e.g., uremia or individuals having abnormally low levels of albumin, such as nephrotic syndrome. Free phenytoin in in serum correlates better with the various other free compartments of the body than does the total drug and is probably a better estimate of the "active drug level" at the receptor site and agrees more with the clinical response.
Collect trough just prior to next dose. For patients receiving
fosphenytoin therapy, collect as peak (at least 2 hours after IV
infusion or at least 4 hours after IM injection).
Reported (Analytical Time)
The CPT codes provided are based on AMA guidelines and are for informational purposes only.
CPT coding is the sole responsibility of the billing party.
Please direct any questions regarding coding to the payer being billed.