P.D. is a 10-day-old term infant in the neonatal intensive care unit being treated for seizures. P.D. continues to have seizures despite phenobarbital therapy with a therapeutic phenobarbital concentration of 28 mcg/ mL. The intern wants to load P.D. with phenytoin and begin a maintenance dose of phenytoin. Which is the most appropriate statement regarding phenytoin use in this infant?
A. Phenytoin should not be used in neonates younger than 2 weeks because of the risk of kernicterus.
B. Phenytoin is highly protein bound, and with the altered binding in newborns, monitoring free drug concentrations may be considered.
C. Phenobarbital can induce phenytoin metabolism, so smaller maintenance doses are usually needed.
D. Genotyping before therapy can predict infants likely to experience phenytoin-induced liver toxicity.