Treatment options for acute seizure care - Use of new formulations

The advent of new anticonvulsants, the resurgence of the ketogenic diet, an d the currently available surgical techniques mean that practitioners have many options for long term prophylaxis of seizure recurrence. Unfortunately , break through seizures still occur. In some situations, an additional dos e of the patient's maintenance medication, or adjustment of the dairy dose, is the most appropriate course of action for the management of such breakt hroughs. However, in some situations, the patient may be unwilling or unabl e to cooperate and so oral administration of anticonvulsants is not possibl e. Until recently, only benzodiazepines, phenytoin and phenobarbital (pheno barbitone) have been available for parenteral administration: however, alte rnative treatment options have been developed: diazepam gel for rectal admi nistration, fosphenytoin (a phenytoin prodrug) and an intravenous formulati on of valproic acid (sodium valproate). An intravenous formulation of diazepam has been long used for seizure treat ment and has shown good efficacy. The gel formulation showed >60% efficacy for preventing seizures over 12 to 24 hours in 2 controlled studies. No lif e-threatening adverse reactions were reported. Fosphenytoin is rapidly conv erted to phenytoin with a conversion half-life of 8 to 15 minutes following intravenous administration, and can be given in a variety of solutions. It map also be administered intramuscularly. Fosphenytoin infusion has not be en associated with tissue necrosis and there have been fewer cardiac compli cations than are seen with intravenous infusion of phenytoin. Intravenous v alproic acid shows linear pharmacokinetics, and administration by this rout e has been demonstrated to maintain therapeutic concentrations in patients and offers an alternative when patients cannot take the drug orally. Intrav enous valproic acid has been shown to be well tolerated.