Posttraumatic Epilepsy Prophylaxis

Abstract

Despite a large body of experimental evidence suggesting that post-traumatic epilepsy can be prevented, there is no generally accepted pharmacological regimen for post-traumatic seizure prophylaxis. A phenytoin anticonvulsant regimen specifically tailored for the patient with acute head injury and designed to provide immediate and sustained plasma concentrations of phenytoin between 10-20 .mu.g/ml is described. Initially, an i.v. phenytoin dose of 11 mg/kg body weight is immediately followed by an i.m. dose of 13 mg/kg body weight. This is followed by daily i.m. maintenance doses, usually 8.8 mg/kg body weight, until oral medication can be tolerated. Maintenance dosage adjustments, when necessary, are based on serial plasma concentrations of the drug. Patients [84] with severe head injuries with substantial risk of post-traumatic epilepsy were administered this regimen. Only 6% of these patients had seizures during the 1st yr after injury (1st wk excluded), and this is considerably less than the rates reported elsewhere in the literature. Only 1/3 of these patients are known to have continued to take phenytoin after the 1st mo., and only half of these had plasma phenytoin concentrations above the desired minimal level. The greatly reduced incidence of post-traumatic seizures in these patients, despite the low rate of long-term drug compliance, suggests that a prophylactic effect, rather than a suppressive effect, is produced.