[Efficient serum concentrations after single doses of antiepileptic drugs: concept of loading-dose].

Single doses of phenytoin (500 and 1.000 mg), carbamazepine 400 and 1.00 mg) and sodium valproate (600 mg) were given orally to 5 healthy young volunteers and serum concentrations determined between 1-8h after administration. The design was double-blind and placebo-controlled. Serum concentrations considered "therapeutic" were obtained after sodium valproate and the 100 mg dose of carbamazepine. The results suggest the loading-doses of phenytoin (1500-2000 mg) and carbamazepine (800 mg) are useful in the subacute control of frequent epileptic seizures on an out-patient basis, and that carbamazepine may be used for lasting control of seizures of status epilepticus treated initially with diazepam or other rapidly-acting preparation.