A pharmacoeconomic evaluation of intravenous fosphenytoin (Cerebyx) versus intravenous phenytoin (Dilantin) in hospital emergency departments

A critical review of fosphenytoin sodium injection for the treatment of status epilepticus in adults and children

INTRODUCTION

Status epilepticus (SE) is a neurological emergency that can occur in patients with or without epilepsy. Rapid treatment is paramount to mitigate risks of neuronal injury, morbidity/mortality, and healthcare-cost burdens associated with SE. Fosphenytoin is the prodrug of phenytoin designed to enable faster administration and improved tolerability as compared to intravenous (IV) phenytoin in the treatment of SE.

AREAS COVERED

This review evaluates the chemistry, pharmacokinetics, pharmacodynamics, safety, and tolerability of fosphenytoin. Efficacy data for fosphenytoin in the treatment of SE in adults and children are analyzed from initial phase I trials in 1988 through current phase III trials, including the Established Status Epilepticus Treatment Trial (ESETT).

EXPERT OPINION

IV phenytoin is an established treatment of SE, but its alkaline aqueous vehicle is associated with dermatologic irritation and systemic complications when rapidly infused. The water-soluble nature of its prodrug, fosphenytoin, allows for rapid infusion, and it is rapidly converted to phenytoin when administered intravenously or intramuscularly. In the ESETT, IV fosphenytoin demonstrated similar efficacy in treatment of established SE when compared to IV levetiracetam and IV valproate in adults and children, making it a reasonable choice in the treatment of SE that is unresponsive to benzodiazepines.

A critical appraisal of randomized controlled trials on intravenous phenytoin in convulsive status epilepticus

Since the 1970s, intravenous (IV) phenytoin (PHT) has traditionally been used as second-stage treatment for convulsive status epilepticus (SE) after failure of benzodiazepines. The aim of this review was to critically assess the evidence supporting the use of IV PHT as treatment of convulsive SE in patients of any age. In particular, we critically appraised the results of randomized controlled trials (RCTs) evaluating IV PHT as treatment of convulsive SE. A systematic search of the literature was carried out to identify RCTs evaluating IV PHT as treatment of convulsive SE in patients of any age. Eight RCTs (544 patients allocated to IV PHT) were included. The included studies differed in almost every single characteristic considered. Six RCTs (472 patients) used IV PHT without demonstrating refractoriness of SE to benzodiazepines. Only two RCTs (72 patients) used IV PHT as second-line treatment for benzodiazepine-resistant convulsive SE. Overall, most evidence from RCTs supports the use of IV PHT immediately after IV diazepam, even if seizures have not recurred. The recommendation derived from RCTs supporting the use of IV PHT as second-line treatment in benzodiazepine-resistant convulsive SE is weak. This is emblematic of the lack of robust evidence from large RCTs to inform clinical practice on how to treat SE after failure of first-line drugs. IV PHT given immediately after first-line benzodiazepines could prolong their short antiepileptic effect and prevent seizure recurrence.

Status Epilepticus: What's New?

The emergent evaluation and treatment of generalized convulsive status epilepticus presents challenges for emergency physicians. This disease is one of the few in which minutes can mean the difference between life and significant morbidity and mortality. It is imperative to use parallel processing and have multiple treatment options planned in advance, in case the current treatment is not successful. There is also benefit to exploring, or initiating, treatment algorithms to standardize the care for these critically ill patients.

Cardiovascular adverse effects of phenytoin

Phenytoin is an established drug in the treatment of acute repetitive seizures and status epilepticus. One of its main advantages over benzodiazepines is the less sedative effect. However, the possibility of cardiovascular adverse effects with the intravenous use of phenytoin cause a reluctance to its usage, and this has lead to a search for safer anticonvulsant drugs. In this study, we aimed to review the studies which evaluated the safety of phenytoin with respect to cardiovascular adverse effects. The original clinical trials and case reports listed in PUBMED in English language between the years of 1946-2014 were evaluated. As the key words, "phenytoin, diphenylhydantoin, epilepsy, seizure, cardiac toxicity, asystole, arrhythmia, respiratory arrest, hypotension, death" were used. Thirty-two clinical trials and ten case reports were identified. In the case reports, a rapid infusion rate (>50 mg/min) of phenytoin appeared as the major cause of increased mortality. In contrast, no serious cardiovascular adverse effects leading to death were met in the clinical trials which applied the recommended infusion rate and dosages. An infusion rate of 50 mg/min was reported to be safe for young patients. For old patients and patients with a cardiovascular co-morbidity, a slower infusion rate was recommended with a careful follow-up of heart rhythm and blood pressure. No cardiovascular adverse effect was reported in oral phenytoin overdoses except one case with a very high serum phenytoin level and hypoalbuminemia. Phenytoin is an effective and well tolerated drug in the treatment of epilepsy. Intravenous phenytoin is safe when given at recommended infusion rates and doses.

Evaluation of intramuscular fosphenytoin vs intravenous phenytoin loading in the ED

OBJECTIVE

A comparison of length of stay in an emergency department (ED) after loading patients at risk for seizures with either intravenous (IV) phenytoin or intramuscular (IM) fosphenytoin was studied.

METHODS

This was a retrospective observational cohort study that was conducted over a 24-month period in an academic teaching hospital (693 beds). Patients included were 18 years or older, discharged from the ED without hospital admission, and loaded with either IV phenytoin or IM fosphenytoin. The primary end point was the comparison of length of stay in the ED until discharge after loading. Characterization of seizure etiology, cardiac risk factors, and adverse drug events were also observed.

RESULTS

A total of 51 patients were evaluated who received IV phenytoin compared with 59 for IM fosphenytoin. The median time-to-discharge difference between IV phenytoin vs IM fosphenytoin was 1:49 hours (95% confidence interval, 1:24-2:24 hours; P < .001). There was no statistical difference in cardiac risk factors and occurrence of adverse drug events between groups.

CONCLUSIONS

This study found that patients were discharged from the ED earlier with the loading of IM fosphenytoin compared to IV phenytoin.

Intravenous sodium valproate in mainland China for the treatment of diazepam refractory convulsive status epilepticus

The purpose of this study was to identify the short-term safety and efficacy of treating patients with intravenous (i.v.) sodium valproate (VPA) for diazepam (DZP) refractory convulsive status epilepticus (CSE). We prospectively registered 48 patients with refractory CSE who were treated at West China Hospital with i.v. VPA (30mg/kg, 6mg/kg per hour) after a loading dose of i.v. DZP and intramuscular phenobarbitone (PBT) failed. VPA stopped seizures in 87.5% of patients within 1h, and patients regained baseline mental status within 1h of seizure cessation. CSE did not recur in patients within the next 12h, and no significant VPA-related systemic or local side effects were found during their hospital stay. In conclusion, this study suggests that i.v. VPA is a promising option for DZP refractory CSE in mainland China, since i.v. PBT is unavailable in most hospitals, and anesthesia is unacceptable to most of the Chinese population.

Posterior reversible encephalopathy syndrome: an emerging clinical entity in adult, pediatric, and obstetric critical care

PURPOSE

To describe the signs, symptoms, causative factors, and treatment for posterior reversible encephalopathy syndrome (PRES), an emerging clinical neuroradiologic entity which may be encountered by nurse practitioners in almost any clinical setting.

DATA SOURCES

Extensive review of worldwide literature, including peer-reviewed medical specialty journals, supplemented by an actual case study. Currently, a paucity of information exists in the nursing literature.

CONCLUSIONS

PRES occurs as a result of disordered cerebral circulatory autoregulation and/or endothelial dysfunction, usually as a result of acute, intermittent hypertension. Clinical manifestations include mental status change, headache, visual disturbance, and seizures. Characteristic abnormalities in the posterior cerebral white matter, seen best on diffusion-weighted magnetic resonance imaging, confirm the presence of the syndrome. PRES has been documented worldwide among a diverse patient population, yet many clinicians are still unfamiliar with this diagnosis.

IMPLICATIONS FOR PRACTICE

PRES is a clinical-radiographic diagnosis that requires close collaboration between the clinician and interpreting radiologist. Rapid identification and appropriate diagnostics are essential, as prompt treatment usually results in reversal of symptoms; permanent neurologic injury or death can occur with treatment delay.

Prescribing antiepileptic drugs: should patients be switched on the basis of cost?

To assess the costs of switching from one antiepileptic drug (AED) to another, all associated direct and indirect costs, not only drug acquisition costs, must be considered. The perspective of the healthcare system evaluated in cost-effectiveness analysis is of crucial importance. Multiple clinical factors can influence clinical decisions regarding switching AEDs. The economic cost of poorly controlled epilepsy is enormous and the most cost-effective intervention is an AED that provides total seizure control. Cost-minimisation studies have evaluated costs associated with various medications. If only efficacy and adverse events were considered, then the 'older' AEDs were generally more cost effective than the 'newer' AEDs. Most studies only examine very specific clinical situations and are not suitable for establishing general clinical recommendations. The pharmacoeconomics of AED choice is highly country specific. While switching to generic formulations is, in general, cost effective, some changes may be detrimental and more costly than remaining on the trade name preparation. For example, as a result of differences in bioavailability and possible loss of seizure control, changing patients to generic phenytoin and carbamazepine can be problematic. Fosphenytoin may only be cost effective in certain clinical situations compared with intravenous phenytoin. Seizure control should not be sacrificed on the basis of costs alone, as the major endpoint in treating epilepsy with AEDs is seizure control without adverse effects. Switching AEDs in clinical practice still depends on the individual clinical situation and choosing AED therapy solely on the basis of initial acquisition costs is unlikely to be cost effective in the long-term care of patients with epilepsy.

Cost-effectiveness of oral phenytoin, intravenous phenytoin, and intravenous fosphenytoin in the emergency department

STUDY OBJECTIVE

Oral phenytoin, intravenous phenytoin, and intravenous fosphenytoin are all commonly used for loading phenytoin in the emergency department (ED). The cost-effectiveness of each was compared for patients presenting with seizures and subtherapeutic phenytoin concentrations.

METHODS

A simple decision tree was developed to determine the treatment costs associated with each of 3 loading techniques. We determined effectiveness by comparing adverse event rates and by calculating the time to safe ED discharge. Time to safe ED discharge was defined as the time at which therapeutic concentrations of phenytoin (>or=10 mg/L) were achieved with an absence of any adverse events that precluded discharge. The comparative cost-effectiveness of alternatives to oral phenytoin was determined by combining net costs and number of adverse events, expressed as cost per adverse events avoided. Cost-effectiveness was also determined by comparing the net costs of each loading technique required to achieve the time to safe ED discharge, expressed as cost per hour of ED time saved. The outcomes and costs were primarily derived from a prospective, randomized controlled trial, augmented by time-motion studies and alternate-cost sources. Costs included the cost of drugs, supplies, and personnel. Analyses were also performed in scenarios incorporating labor costs and savings from using a lower-urgency area of the ED.

RESULTS

The mean number of adverse events per patient for oral phenytoin, intravenous phenytoin, and intravenous fosphenytoin was 1.06, 1.93, and 2.13, respectively. Mean time to safe ED discharge in the 3 groups was 6.4 hours, 1.7 hours, and 1.3 hours. Cost per patient was 2.83 dollars, 21.16 dollars, and 175.19 dollars, respectively, and did not differ substantially in the Labor and Triage (lower-urgency area of ED) scenarios. When the measure of effectiveness was adverse events, oral phenytoin dominated intravenous phenytoin and intravenous fosphenytoin, with a lower cost and number of adverse events. With time to safe ED discharge as the outcome measure, the incremental cost-effectiveness ratios were 3.90 dollars and 387.27 dollars per hour of ED time saved for oral phenytoin versus intravenous phenytoin and for intravenous fosphenytoin versus intravenous phenytoin, respectively.

CONCLUSION

Oral phenytoin is the most cost-effective loading method in most settings. Intravenous phenytoin is preferred if one is willing to pay an additional 20.65 dollars to 44.25 dollars per patient and willing to have more adverse events for a quicker average time to safe ED discharge. It is unlikely that intravenous fosphenytoin is justifiable in any setting.

A comparison of phenytoin-loading techniques in the emergency department

OBJECTIVES

To compare the effectivenesses of three phenytoin-loading techniques.

METHODS

Patients with subtherapeutic phenytoin concentrations who presented within 48 hours of a seizure were randomized to receive either 20 mg/kg of oral phenytoin (PO), divided in maximum doses of 400 mg every two hours, 18 mg/kg of intravenous phenytoin (IVP) at an initial infusion rate of 50 mg/min, or 18 mg/kg (phenytoin equivalents) of intravenous fosphenytoin (IVF) at an initial infusion rate of 150 mg/min.

RESULTS

A total of 45 patients were enrolled: 16 in the PO group, 14 in the IVP group, and 15 in the IVF group. The times required to reach therapeutic drug concentrations were (mean +/- standard deviation [SD]) 5.62 +/- 0.28 hours, 0.24 +/- 0.3 hours, and 0.21 +/- 0.28 hours, respectively. A total of 17, 27, and 32 adverse drug events were observed in the PO, IVP, and IVF groups, respectively, with significantly fewer events in the PO group (p = 0.02, p = 0.01). No significant difference was found between the numbers of necessary adjustments to the infusions in the two IV groups. The average time to safe emergency department discharge was significantly shorter for the IV groups compared with the PO group (p < 0.001).

CONCLUSIONS

Oral loading has fewer adverse drug events than either IV loading method, but its use may be limited when therapeutic concentrations are required quickly. Although IVF loading is faster, from an adverse-drug event perspective, no advantage of IVF over IVP was apparent.

Adverse events associated with intravenous phenytoin in children: a prospective study

A prospective study was undertaken to assess the type and frequency of adverse side-effects following the use of intravenous phenytoin in children. Twenty-two children received a total of 100 doses over a 10-month period. Six patients (27%) experienced one or more side-effects, including extravasation of the drug, hypotension and cardiac arrhythmia. No patient developed skin necrosis, including the 'purple glove syndrome'. Recovery from all adverse side-effects was spontaneous and complete. It is possible that some or all of these side-effects may have been caused by an excessive rate of infusion of phenytoin or the saline 'flush' following administration of the drug. The overall frequency of side-effects was perhaps less than expected.

Fosphenytoin: clinical pharmacokinetics and comparative advantages in the acute treatment of seizures

Fosphenytoin is a phosphate ester prodrug developed as an alternative to intravenous phenytoin for acute treatment of seizures. Advantages include more convenient and rapid intravenous administration, availability for intramuscular injection, and low potential for adverse local reactions at injection sites. Drawbacks include the occurrence of transient paraesthesias and pruritus at rapid infusion rates, and cost. Fosphenytoin is highly bound (93-98%) to plasma proteins. Saturable binding at higher plasma concentrations accounts for an increase in its distribution volume and clearance with increasing dose and infusion rate. Fosphenytoin is entirely eliminated through metabolism to phenytoin by blood and tissue phosphatases. The bioavailability of the derived phenytoin relative to intravenous phenytoin is approximately 100% following intravenous or intramuscular administration. The half-life for conversion of fosphenytoin to phenytoin ranges from 7-15 minutes. Faster intravenous infusion rates and competitive displacement of derived phenytoin from plasma protein binding sites by fosphenytoin compensate for the expected conversion-related delay in appearance of phenytoin in the plasma. Unbound phenytoin plasma concentrations achieved with intravenous fosphenytoin loading doses of 100-150 or 50-100mg phenytoin sodium equivalents/min are comparable, and achieved at similar times, to those with equimolar doses of intravenous phenytoin at 50 (maximum recommended rate) or 20-40 mg/min, respectively. The rapid achievement of effective concentrations permits the use of fosphenytoin in emergency situations, such as status epilepticus. Following intramuscular administration, therapeutic phenytoin plasma concentrations are observed within 30 minutes and maximum plasma concentrations occur at approximately 30 minutes for fosphenytoin and at 2-4 hours for derived phenytoin. Plasma concentration profiles for fosphenytoin and total and unbound phenytoin in infants and children closely approximate those in adults following intravenous or intramuscular fosphenytoin at comparable doses and infusion rates. Earlier and higher unbound phenytoin plasma concentrations, and thus an increase in systemic adverse effects, may occur following intravenous fosphenytoin loading doses in patients with a decreased ability to bind fosphenytoin and phenytoin (renal or hepatic disease, hypoalbuminaemia, the elderly). Close monitoring and reduction in the infusion rate by 25-50% are recommended when intravenous loading doses of fosphenytoin are administered in these patients. The potential exists for clinically significant interactions when fosphenytoin is coadministered with other highly protein bound drugs. The pharmacokinetic properties of fosphenytoin permit the drug to serve as a well tolerated and effective alternative to parenteral phenytoin in the emergency and non-emergency management of acute seizures in children and adults.

A prospective study of the incidence of the purple glove syndrome

PURPOSE

Phenytoin (PHT) has been widely used intravenously for the treatment of seizures since 1956, and for many years, it has been considered first-line therapy for status epilepticus. It is routinely administered intravenously in emergency departments and hospitals for patients who have had isolated seizures and for many patients undergoing neurosurgical procedures who are unable to receive oral medication. Adverse reactions from PHT have been widely studied for years, but in the past decade, new adverse reactions have been identified. One of these adverse reactions is the purple glove syndrome (PGS), characterized by edema, discoloration, and pain distal to the site of i.v. administration of PHT. Because there have been no prospective reports of the incidence of PGS, the objective of the study was to report the incidence of this syndrome.

METHODS

We enrolled 179 consecutive exposures to i.v. PHT at Henry Ford Hospital. Distal portions of the upper extremities were examined and digitally photographed by one of the authors (J.G.B.). The photos were blindly evaluated by the third author (G.L.B.) for PGS. Demographic and pertinent medical history was recorded for all patients, and outcome for those who experienced PGS was recorded. Associations between PGS, demographic, and medical history information were assessed.

RESULTS

In only three of the 179 exposures did PGS develop. In both patients, the severity of the clinical picture was mild and did not required prolonged hospitalization or specialized treatment.

CONCLUSIONS

PGS is an infrequent and mild adverse effect of i.v. PHT administration.

Cost-minimization analysis of phenytoin and fosphenytoin in the emergency department

STUDY OBJECTIVE

To determine the value of fosphenytoin compared with phenytoin for treating patients admitted to an emergency department following a seizure.

DESIGN

Cost-minimization analysis performed from a hospital perspective.

SETTING

Hospital emergency department.

PATIENTS

Two hundred fifty-six patients participating in a comparative clinical trial.

INTERVENTION

Estimation of adverse event rates and resource use.

MEASUREMENTS AND MAIN RESULTS

In our base case, phenytoin was the preferred option, with an expected total treatment cost of $5.39 compared with $110.14 for fosphenytoin. One-way sensitivity analyses showed that the frequency and cost of treating purple glove syndrome (PGS) possibly could affect the decision. Monte Carlo simulation showed phenytoin to be the preferred option 97.3% of the time.

CONCLUSION

When variable costs of care are used to calculate the value of phenytoin compared with fosphenytoin in the emergency department, phenytoin is preferred. The decision to administer phenytoin was very robust and changed only when both the frequency and cost of PGS was high.

Fosphenytoin and phenytoin in patients with status epilepticus: improved tolerability versus increased costs

Tonic-clonic status epilepticus (TCSE) is the most common neurological emergency and affects approximately 60000 patients each year in the US. The risk of complications increases substantially as TCSE lasts longer than 60 minutes. Ideally, drugs used to treat this condition should be well tolerated when administered as rapid intravenous infusions and should not interfere with patients' state of consciousness or cardiovascular and respiratory functions. Because of its efficacy, absence of sedation or respiratory suppression, intravenous phenytoin has largely replaced phenobarbital (phenobarbitone) as the second agent of choice (following the administration of a benzodiazepine) in the treatment of TCSE. While the efficacy of phenytoin in the treatment of acute seizures and TCSE is well established, the parenteral formulation of phenytoin has several inherent shortcomings which compromise its tolerability and limit the rate of administration. Intravenous phenytoin has been associated with fatal haemodynamic complications and serious reactions at the injection site including skin necrosis and amputation of extremities. Fosphenytoin, a phenytoin prodrug, has the same pharmacological properties as phenytoin but none of the injection site and cardiac rhythm complications of intravenous infusions of phenytoin. While fosphenytoin costs more than intravenous phenytoin, treating the acute and chronic complications of TCSE itself, and the complications of intravenous phenytoin can also be costly. All other factors being equal, there is no doubt that fosphenytoin is better tolerated and can be delivered faster than intravenous phenytoin; 2 measures that clearly improve outcome in patients with TCSE. The tolerability of intramuscular fosphenytoin also extends its use to clinical situations where prompt administration of a nondepressing anticonvulsant is indicated but secure intravenous access and cardiac monitoring are not available, such as treatment of seizures by rescue squads in the field and serial seizures in the institutionalised, elderly and other patients with intractable epilepsy.

New formulations of drugs in epilepsy

The advent of numerous new treatment options in epilepsy therapy over the last decade is enabling a more flexible and individualized approach to patients with seizures. For some patients, these products offer added efficacy, reduction of troublesome side effects associated with standard anticonvulsants, and control over acute seizure exacerbations. This review profiles new formulations of anti-epileptic drugs. Tegretol-XR (TXR) and Carbatrol (CBTL), two extended-release preparations of carbamazepine (CBZ), which allow twice daily administration, minimising drug toxicity and improving efficacy. Topiramate sprinkles and lamotrigine chewable dispersible tablets allow easier administration in children. The rectal gel preparation of diazepam (Diastat) is useful for parents of patients with acute seizure exacerbations. Intravenous valproate (Depacon) and fosphenytoin (Cerebyx) provide parenteral treatment of acute seizures, without sedation or significant peripheral venous side effects. All of these new formulations expand treatment options for patients with epilepsy, who will benefit from them.

Convulsive Status Epilepticus

Generalized convulsive status epilepticus (GCSE) is a medical emergency that must be treated rapidly and aggressively to prevent neuronal damage. Treatment should be initiated with intravenous lorazepam, 0.1 mg/kg, given at a rate of no more than 2 mg/min. If convulsions persist for more than 10 minutes or recur more than 20 minutes after lorazepam therapy is started, then fosphenytoin (20 mg of phenytoin equivalents per kilogram) should be infused at a rate of no more than 150 mg/min. If convulsions still continue, intravenous general anesthesia with pentobarbital, benzodiazepine drip, or propofol should be initiated after respiratory support has been established. All patients with GCSE who do not recover consciousness should be monitored with electroencephalography (EEG), and any residual epileptiform activity on EEG, including periodic epileptiform discharges (PEDs), should be considered evidence of continuing GCSE and treated aggressively.

Phenytoin and fosphenytoin: a model of cost and clinical outcomes

We developed a pharmacoeconomic model to compare costs and clinical outcomes of administering phenytoin and fosphenytoin alone and in combination in hospitalized patients. Effectiveness data were obtained by distributing a questionnaire to 33 registered nurses at three acute care hospitals who worked in critical care, neurology services, or emergency department. The questionnaire addressed methods of phenytoin and fosphenytoin administration, frequency of adverse reactions, methods of treating adverse reactions, and demographic information. The model estimated that if 50% of phenytoin loading doses were substituted with fosphenytoin, a reduction in adverse events resulted in an estimated increase of $36/patient cost to the hospital. If phenytoin maintenance dosages were substituted with fosphenytoin, the model predicted essentially no change in cost to the hospital. It appears that fosphenytoin reduces adverse events at a reasonable increase in total hospital costs.

Pharmacoeconomic considerations in treatment options for acute seizures

Two pharmacoeconomic studies on the treatment of acute seizures have been conducted. In 1991, Kriel and colleagues surveyed parents of children with a history of cluster seizures, prolonged seizures, or status epilepticus who had been instructed in the use of rectal diazepam. A comparison of data before instruction with data after instruction showed a reduced need for emergency department visits with rectal diazepam. Instruction thus provided a pharmacoeconomic benefit, despite the cost of the product. In 1996, Marchetti and coworkers found that intravenous fosphenytoin was associated with fewer adverse events than intravenous phenytoin. Fosphenytoin thus reduced the need for adverse event management and provided a substantial pharmacoeconomic benefit, despite its higher cost, compared with phenytoin. This study had a number of limitations, however, and hospital pharmacists remain resistant to the use of fosphenytoin. Additional studies may provide more pharmacoeconomic data to support the greater use of fosphenytoin in the treatment of acute pediatric seizures.

Recent advances in the pharmacotherapy of epilepsy

The therapeutic options for the treatment of epilepsy have expanded during the 1990s. Since 1993, four novel agents (felbamate, gabapentin, lamotrigine, and topiramate) have been approved by the US Food and Drug Administration, primarily for adjunctive treatment of partial seizures. In addition, a water-soluble pro-drug of phenytoin, fosphenytoin, and a sustained-release preparation of carbamazepine have been introduced. The novel anticonvulsants represent a potential improvement for patients whose seizures are incompletely controlled or who experience significant adverse effects with older anticonvulsants. Felbamate, lamotrigine, and topiramate appear to have a broad spectrum of action in seizure control, but felbamate use is limited by the potential for serious adverse effects. Gabapentin, lamotrigine, and topiramate are all well tolerated. Gabapentin has no known drug interactions, whereas lamotrigine and topiramate have limited interactions compared with older agents. The sustained-release preparation of carbamazepine may decrease the incidence of adverse effects and increase patient compliance. Fosphenytoin offers a safer method for intravenous administration of phenytoin and the added flexibility of intramuscular administration. Taken together, these recent advances in treatment may bring about improved efficacy and decreased adverse effects for many patients with epilepsy.