Phenytoin pediatric patients

A pediatric patient was presented to the emergency room (ER) experiencing seizures for which 150-mg Cerebyx (fosphenytoin anticonvulsant) IV was ordered. The pharmacy technician took the call for Cerebyx and delivered three 10-mL vials of Cerebyx 50-mg PE (phenytoin sodium equivalents) per mL to the ER as a floor stock transaction. A nurse misread the 50-mg PE/mL on the 10-mL container label, making the assumption that the entire vial contained 50 mg PE. The contents of all three vials were prepared for administration. Instead of 150 mg PE, the patient was administered ten times the intended dose, or 1,500 mg PE. The patient later died. The ER staff only discovered the error after the patient s blood phenytoin levels were returned from the laboratory. 

Adverse reactions include nystagmus, dizziness, and ataxia. Paresthesias and pruritus typically disappear within 5 to 10 minutes after the infusion. In adults, the rate of administration should be 100 to 150 mg PE/min. Pediatric patients should receive fosphenytoin at a rate of 1 to 3 mg PE/kg/min. Continuous ECG, blood pressure, and respiratory status monitoring is recommended for aU loading doses of fosphenytoin. Seram phenytoin concentrations should not be obtained for at least 2 hours after IV and 4 hours after intramuscular administration of fosphenytoin. 

The stereoselective metabolism of the drug was monitored using a p-CD CSP and mobile phase of water/acetonitrile (80 20) (see Fig, 7), The chronic treatment of 22 pediatric patients with phenytoin alone or in combination with phenobarbital was monitored using this method, and it was found that the S-(—) metabolite was favored over the R-(+) metabolite by a ratio of approximately 9 1. 

If an i.v. line cannot be placed, the intraosseous drug administration route can be used for pediatric patients during, for example, cardiopulmonary resuscitation (CPR) because drug delivery by this route is similar to that for i.v. administration.If drug or fluid deliver by this route is sluggish, a saline flush can be used to clear the needle. Intraosseous administration is used to deliver medications such as epinephrine, atropine, sodium bicarbonate, dopamine, diazepam, isoproterenol, phenytoin, phenobarbital, dexametha-sone, and various antibiotics. ... 

Powell DA, Nahata MC, Durrell DC, Glazer JP, Hilty MD. Interactions among chloramphenicol, phenytoin, and phenobarbital in a pediatric patient. J Pediatr 1981 98(6) 1001-3. 

Although refractory GCSE has been treated with a variety of agents, some practitioners have advocated not only that midazolam should be the first-line agent in refractory GCSE but also that it should be the third-line agent in patients unresponsive to lorazepam plus phenytoin. Table 55-4 contains the loading and maintenance doses for adult and pediatric patients. The continuous-infusion rate should be increased every 15 minutes until seizures are controlled. Most patients respond within 65 minutes. 

Battino D, Estienne M, Avanzini G. Clinical pharmacokinetics of antiseizure drugs in pediatric patients. Part II. Phenytoin, carbamazepine, sulthiame, lamotrigine, vigabatrin, oxcarbazepine, and felbamate. Clin Pharmacokinet 1995 29 341-369. 

G. L. Kearns, S. F. Kemp, C. P. Turley and D. L. Nelson, Protein binding of phenytoin and lidocaine in pediatric patients with type I diabetes mellitus, Dev. Pharmacol Ther., 1988, 11, 14-23. 

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