Incidence and clinical consequence of the purple glove syndrome in patients receiving intravenous phenytoin

Phenytoin Induced Purple Glove Syndrome: An Effective Management Technique

Background: Purple glove syndrome (PGS) is a rare condition characterized by limb edema, discoloration, and pain associated with intravenous and oral phenytoin administration. The pathophysiology is poorly understood, and there is no established treatment. Simple cases have previously been managed with hyaluronidase subcutaneous injections, with more severe cases resulting in compartment syndrome, debridement, or even amputation. Methods/Results: In this case report, a 2-year-old boy with status epilepticus developed PGS after receiving intravenous phenytoin via a cannula on the dorsum of the right hand. The patient was successfully managed by locally infiltrating subcutaneous hyaluronidase diffusely to the affected area, titrating its dose to effect, rather than aiming to adhere to any specific dosing limitation. The child was reviewed daily by the Plastic Surgery team until being discharged, and focal lesions began to demarcate after 48 hours, with epidermal loss but no deeper trauma. The epidermis peeled within one month, with healthy underlying skin found underlying when followed up in clinic. Conclusions: This case illustrates that subcutaneous administration of hyaluronidase and titrating to effect provides an effective and safe treatment for treating distal cases of early PGS in children.

Enhancing Oil Solubility of BCS Class II Drug Phenytoin Through Hydrophobic Ion Pairing to Enable High Drug Load in Injectable Nanoemulsion to Prevent Precipitation at Physiological pH With a Potential to Prevent Phlebitis

This work investigates the micellar titration of phenytoin (a weakly acidic drug) with cetyltrimethylammonium hydroxide (CTAH) to form a hydrophobic ion-pair to enhance oil solubility of phenytoin, followed by an effort to formulate nanoemulsion that could potentially prevent precipitation of phenytoin at physiological pH. The ion-pair formulated in nanoemulsion was evaluated for in vitro precipitation during serial dilution at physiological pH. The formation of ion-pair during titration was explained in context of pH-solubility data. The mathematical model successfully integrated ionization and micellization equilibria to reflect on dominant mechanisms for solubilization. The micellar phenomenon during titration was confirmed using Dynamic Light Scattering (DLS). The phase changes of the excess undissolved solids during titration were evident from X-Ray Powder Diffraction (XRPD) and Fourier Transform Infrared Spectroscopy (FTIR). This analysis confirmed the conversion of phenytoin into ionized state and its subsequent ionic interaction with CTAH forming hydrophobic ion-pair complex (HIP). The complete ion pair formation was evident at pHmax (8.8 to 9.2), and its 1:1 stoichiometry was confirmed using HPLC (Phenytoin and CTAH) and H1 NMR, hence could also be called as a lipophilic salt. The ion-pair (salt) was insoluble in water and showed remarkably high partition coefficient (log P) in octanol/water. As characterized by Hot Stage Microscopy (HSM), the melting point of the ion-pair complex was lowered to 150.8⁰C compared to the free acid (> 300οC), this was even further lowered to 81.1 °C when evaluated in castor oil. This led to approximately eight-fold higher solubility of hydrophobic ion pair (HIP) in castor oil compared to the free acid form. The high miscibility in castor oil was suitable to formulate a high drug load injectable dispersed system. This was successfully achieved with lecithin and polysorbate as emulsifiers without leaching drug into continuous phase at pH 7.4. This nanoemulsion (<300 nm, and > +30 mV zeta potential) remain stable when evaluated over a period of one month. A serial dilution study of the nanoemulsion was performed in PBS buffer, microscopic observations suggested no birefringence despite incubation at 25°C for several hours. This result indicated that Phenytoin remained strongly partitioned within dispersed oily phase with a higher drug loading when ion-paired phenytoin was used. The higher drug load could enable a small volume slow bolus injection to meet 50 mg/min or lower delivery rate criteria for Phenytoin in the clinical set up. This provided a pathway to further explore potential injectable nano-emulsion formulations that could alleviate typical phlebitis issue associated with the injectable phenytoin solution administration at physiological pH.

Status Epilepticus in Older Adults: Diagnostic and Treatment Considerations

Status epilepticus (SE) is one of the leading life-threatening neurological emergencies in the elderly population, with significant morbidity and mortality. SE presents unique diagnostic and therapeutic challenges in the older population given overlap with other causes of encephalopathy, complicating diagnosis, and the common occurrence of multiple comorbid diseases complicates treatment. First-line therapy involves the use of rescue benzodiazepine in the form of intravenous lorazepam or diazepam, intramuscular or intranasal midazolam and rectal diazepam. Second-line therapies include parenteral levetiracetam, fosphenytoin, valproate and lacosamide, and underlying comorbidities guide the choice of appropriate medication, while third-line therapies may be influenced by the patient's code status as well as the cause and type of SE. The standard of care for convulsive SE is treatment with an intravenous anesthetic, including midazolam, propofol, ketamine and pentobarbital. There is currently limited evidence guiding appropriate therapy in patients failing third-line therapies. Adjunctive strategies may include immunomodulatory treatments, non-pharmacological strategies such as ketogenic diet, neuromodulation therapies and surgery in select cases. Surrogate decision makers should be updated early and often in refractory episodes of SE and informed of the high morbidity and mortality associated with the disease as well as the high probability of subsequent epilepsy among survivors.

Management of Status Epilepticus and Indications for Inpatient Electroencephalography Monitoring

Status epilepticus (SE) is a neurologic emergency requiring immediate time-sensitive treatment to minimize neuronal injury and systemic complications. Minimizing time to administration of first- and second-line therapy is necessary to optimize the chances of successful seizure termination in generalized convulsive SE (GCSE). The approach to refractory and superrefractory GCSE is less well defined. Multiple agents with differing complementary actions that facilitate seizure termination are recommended. Nonconvulsive SE (NCSE) has a wide range of presentations and approaches to treatment. Continuous electroencephalography is critical to the management of both GCSE and NCSE, while its use for patients without seizure continues to expand.

Antiepileptic Drug Therapy for Status Epilepticus

Status epilepticus (SE) is one of the most serious neurologic emergencies. SE is a condition that encompasses a broad range of semiologic subtypes and heterogeneous etiologies. The treatment of SE primarily involves the management of the underlying etiology and the use of antiepileptic drug therapy to rapidly terminate seizure activities. The Drug Committee of the Korean Epilepsy Society performed a review of existing guidelines and literature with the aim of providing practical recommendations for antiepileptic drug therapy. This article is one of a series of review articles by the Drug Committee and it summarizes staged antiepileptic drug therapy for SE. While evidence of good quality supports the use of benzodiazepines as the first-line treatment of SE, such evidence informing the administration of second- or third-line treatments is lacking; hence, the recommendations presented herein concerning the treatment of established and refractory SE are based on case series and expert opinions. The choice of antiepileptic drugs in each stage should consider the characteristics and circumstances of each patient, as well as their estimated benefit and risk to them. In tandem with the antiepileptic drug therapy, careful searching for and treatment of the underlying etiology are required.

Provision of Sedation and Treatment of Seizures During Neonatal Therapeutic Hypothermia

Hypoxic-ischemic encephalopathy (HIE) produces a high rate of long-term neurodevelopmental disability in survivors. Therapeutic hypothermia dramatically improves the incidence of intact survival, but does not eliminate adverse outcomes. The ideal provision of sedation and treatment of seizures during therapeutic hypothermia represent therapeutic targets requiring optimization in practice. Physiologic stress from therapeutic hypothermia may obviate some of the benefits of this therapy. Morphine is commonly utilized to provide comfort, despite limited empiric evidence supporting safety and efficacy. Dexmedetomidine represents an interesting alternative, with preclinical data suggesting direct efficacy against shivering during induced hypothermia and neuroprotection in the setting of HIE. Pharmacokinetic properties must be considered when utilizing either agent, with safety dependent on conservative dosing and careful monitoring. HIE is the leading cause of neonatal seizures. Traditional therapies, including phenobarbital, fosphenytoin, and benzodiazepines, control seizures in the vast majority of neonates. Concerns about the acute and long-term effects of these agents have led to the exploration of alternative anticonvulsants, including levetiracetam. Unfortunately, levetiracetam is inferior to phenobarbital as first-line therapy for neonatal seizures. Considering both the benefits and risks of traditional anticonvulsant agents, treatment should be limited to the shortest duration indicated, with maintenance therapy reserved for neonates at high risk for recurrent seizures.

Antiepileptic Overdose

Antiepileptics include various groups of drugs that have different mechanisms of actions and adverse effects. They are often also used to treat other disorders such as psychosis, chronic pain, and migraine. The most common drugs implicated in overdose include phenytoin, sodium valproate, carbamazepine, and phenobarbital. Common signs of toxicity of these drugs are central nervous system manifestations such as altered sensorium, lethargy, ataxia, and nystagmus. Some ingestions can paradoxically precipitate seizures and even status epilepticus. Sodium valproate can cause hyperammonemic encephalopathy and cerebral edema. Carbamazepine is implicated in cardiac arrhythmias and hyponatremia. Phenobarbital causes sedation, respiratory depression, and hypotension. In suspected overdose, apart from the routine laboratory tests, serum levels of the drug should be sent. Serial levels should be measured, as drug toxicity can be prolonged. Treatment of all these overdoses begins with stabilization of airway, breathing, and circulation, and endotracheal intubation being performed to protect the airway in patients with altered mental status. For decontamination, a single dose of activated charcoal should be given. Multidose of activated charcoal may be useful in phenytoin, carbamazepine, and phenobarbital overdose. Naloxone and carnitine are indicated in valproate overdose. Carbamazepine overdose can cause a widened QRS complex and arrhythmias, which can be treated with sodium bicarbonate. Forced alkaline diuresis is no longer advocated for phenobarbital poisoning. The Extracorporeal Treatments in Poisoning (EXTRIP) workgroup have formulated guidelines for extracorporeal removal of all these drugs. In most cases, hemodialysis is preferred. Other modalities include charcoal hemoperfusion (especially for carbamazepine) or continuous venovenous hemodialysis. Patients who ingest long-acting preparations should be monitored for longer periods.

Pharmacokinetics and Drug Interaction of Antiepileptic Drugs in Children and Adolescents

Selecting the most appropriate antiepileptic drug (AED) or combination of drugs for each patient and identifying the most suitable therapeutic regimen for their needs is increasingly challenging, especially among pediatric populations. In fact, the pharmacokinetics of several drugs vary widely in children with epilepsy because of age-related factors, which can influence the absorption, distribution, metabolism, and elimination of the pharmacological agent. In addition, individual factors, such as seizure type, associated comorbidities, individual pharmacokinetics, and potential drug interactions, may contribute to large fluctuations in serum drug concentrations and, therefore, clinical response. Therapeutic drug concentration monitoring (TDM) is an essential tool to deal with this complexity, enabling the definition of individual therapeutic concentrations and adaptive control of dosing to minimize drug interactions and prevent loss of efficacy or toxicity. Moreover, pharmacokinetic/pharmacodynamic modelling integrated with dashboard systems have recently been tested in antiepileptic therapy, although more clinical trials are required to support their use in clinical practice. We review the mechanism of action, pharmacokinetics, drug-drug interactions, and safety/tolerability profiles of the main AEDs currently used in children and adolescents, paying particular regard to issues of relevance when treating this patient population. Indications for TDM are provided for each AED as useful support to the clinical management of pediatric patients with epilepsy by optimizing pharmacological therapy.

Purple Glove Syndrome after Phenytoin or Fosphenytoin Administration: Review of Reported Cases and Recommendations for Prevention

The aim of our study was to identify all previously reported cases of phenytoin- or fosphenytoin-associated purple glove syndrome (PGS) and summarize the most current understanding of the pathophysiology, clinical presentation, diagnosis, and treatment of the disease. We searched the English language references from MEDLINE, EMBASE, CINAHL, TOXNET, and gray literature that featured one or more case descriptions of phenytoin- or fosphenytoin-associated PGS after administration and provided information on the clinical setting of the event and associated outcome(s). Descriptive statistics were employed to summarize relevant facts about the cases. We identified 82 unique cases of parenteral phenytoin-associated PGS and 5 cases of fosphenytoin-associated PGS that were published from 1984 to 2015. Additionally, we found two cases of PGS associated with oral formulation of phenytoin published from 1999 to 2015. The spectrum of tissue injury ranged from mild local cutaneous reactions around the infusion site to frank limb ischemia. Just over a half of cases reported symptoms after one dose of IV phenytoin. Pathologic findings included evidence for microvascular thrombosis and possible microvascular or subclinical extravasation as a contributing mechanism. Dopper ultrasound and conventional angiography were used in some patients to identify arterial or venous thrombosis. Various treatments were documented including the use of supportive care such as limb elevation and heat or cold application, utilization of systemic antibiotics, anticoagulants, or vasodilators, and local infiltration of hyaluronidase, heparin, or other compounds. In a small number of patients, invasive interventions such as regional anesthesia, thrombectomy, fasciotomy, and debridement were described. Time to resolution varied from days to weeks. Resolution of PGS without deficits was documented in the majority of cases. Skin changes followed by sensory and motor deficits were described in 16, 6, and 5 cases, respectively. Four patients underwent skin grafting and eight patients required limb amputation. Death as a result of PGS was documented in two patients. PGS associated with oral and injectable phenytoin or parenteral fosphenytoin has been documented in the literature and sometimes includes significant vascular thrombosis and potentially limb-threatening ischemia. Avoidance of small hand veins, adherence to recommended IV administration guidelines and monitoring of the infusion site for reactions should be considered to decrease the morbidity of IV phenytoin or fosphenytoin use. Patients with PGS and evidence of decreased distal perfusion should undergo prompt vascular imaging and potential intervention to avoid ischemic sequelae. Alternative anticonvulsant drugs should be considered in patients at risk for PGS when possible.

Purple glove syndrome following intravenous phenytoin administration

Purple glove syndrome (PGS) is a rare complication of intravenous phenytoin use that typically presents with pain, edema, and discoloration at the injection site that spreads to the distal limb. Several risk factors have been associated with the development of PGS; however, the etiology remains unknown. We present a case of PGS and briefly review the current understanding of this syndrome.

A review of chemical burns

Chemical Burns make up 3% of burns center admissions and have a mortality rate that varies from 4.1 to 13%. There are over 25,000 products capable of causing chemical burns. These injuries may cause significant tissue necrosis and have the potential for systemic toxicity. This article gives an overview of the various types of chemical burns along with their management. Chemical warfare agents and extravasation injuries will also be briefly discussed.

An anaesthesiologist's encounter with purple glove syndrome

Purple glove syndrome (PGS) is a devastating complication of intravenous (IV) phenytoin administration. Anaesthetic management during the amputation of the limb for such patients is very challenging due to limited clinical experience. A 65-year-old woman developed PGS of left upper extremity after IV administration of phenytoin following generalised tonic-clonic seizures. The condition progressed rapidly leading to gangrene of left hand extending to the mid arm. Amputation was carried out under general anaesthesia with a supraglottic airway device. We discuss the prevention and alternate managements in PGS, which is a rare clinical entity with limited data in the literature.

Intravenous and Intramuscular Formulations of Antiseizure Drugs in the Treatment of Epilepsy

Intravenous and intramuscular antiseizure drugs (ASDs) are essential in the treatment of clinical seizure emergencies as well as in replacement therapy when oral administration is not possible. The parenteral formulations provide rapid delivery and complete (intravenous) or nearly complete (intramuscular) bioavailability. Controlled administration of the ASD is feasible with intravenous but not intramuscular formulations. This article reviews the literature and discusses the chemistry, pharmacology, pharmacokinetics, and clinical use of currently available intravenous and intramuscular ASD formulations as well as the development of new formulations and agents. Intravenous or intramuscular formulations of lorazepam, diazepam, midazolam, and clonazepam are typically used as the initial treatment agents in seizure emergencies. Recent studies also support the use of intramuscular midazolam as easier than the intravenous delivery of lorazepam in the pre-hospital setting. However, benzodiazepines may be associated with hypotension and respiratory depression. Although loading with intravenous phenytoin was an early approach to treatment, it is associated with cardiac arrhythmias, hypotension, and tissue injury at the injection site. This has made it less favored than fosphenytoin, a water-soluble, phosphorylated phenytoin molecule. Other drugs being used for acute seizure emergencies are intravenous formulations of valproic acid, levetiracetam, and lacosamide. However, the comparative effectiveness of these for status epilepticus (SE) has not been evaluated adequately. Consequently, guidelines for the medical management of SE continue to recommend lorazepam followed by fosphenytoin, or phenytoin if fosphenytoin is not available. Intravenous solutions for carbamazepine, lamotrigine, and topiramate have been developed but remain investigational. The current ASDs were not developed for use in emergency situations, but were adapted from ASDs approved for chronic oral use. New approaches for bringing drugs from experimental models to treatment of human SE are needed.

Phenytoin-Induced Purple Glove Syndrome: A Case Report and Review of the Literature

OBJECTIVE

To present a case report and literature review of phenytoin-induced purple glove syndrome (PGS).

CASE SUMMARY

A 54-year-old African American male presented to our hospital's emergency department (ED) following a seizure episode, cardiac arrest, and loss of consciousness. On arrival to the ED, the patient's total phenytoin level was subtherapeutic at 4.1 mcg/mL and his corrected total phenytoin level was subtherapeutic at 5.1 mcg/mL. In the ED, the patient received a loading dose of intravenous (IV) phenytoin 1,000 mg once via the left cephalic vein, at a rate of 50 mg/min, and was admitted to the medicine service. A day following IV phenytoin administration, a nurse noticed an IV fluid infiltration on the skin tissue around the left cephalic vein. The area appeared dark blue and purple in color, swollen, erythematous, and warm to touch. An ultrasound of the left upper extremity was performed and revealed subcutaneous fluid collection without evidence of thrombosis.

DISCUSSION

The Naranjo Adverse Drug Reaction Probability Scale assigned a score of 7, indicating phenytoin as the probable cause of purple glove syndrome (PGS). The patient's PGS was managed with a combination of dry dressing material, left forearm elevation, collagenase topical cream, 0.1% IV bupivacaine, and IV fentanyl. The patient's injury was resolving at the time of discharge to a rehabilitation facility.

CONCLUSION

PGS is a rare complication of IV phenytoin therapy. The risk of PGS for this patient may have been abated by decreasing the phenytoin infusion rate from 50 mg/min to less than 25 mg/min.

Pharmacotherapy for Status Epilepticus

Status epilepticus (SE) represents the most severe form of epilepsy. It is one of the most common neurologic emergencies, with an incidence of up to 61 per 100,000 per year and an estimated mortality of 20 %. Clinically, tonic-clonic convulsive SE is divided into four subsequent stages: early, established, refractory, and super-refractory. Pharmacotherapy of status epilepticus, especially of its later stages, represents an "evidence-free zone," due to a lack of high-quality, controlled trials to inform clinical decisions. This comprehensive narrative review focuses on the pharmacotherapy of SE, presented according to the four-staged approach outlined above, and providing pharmacological properties and efficacy/safety data for each antiepileptic drug according to the strength of scientific evidence from the available literature. Data sources included MEDLINE and back-tracking of references in pertinent studies. Intravenous lorazepam or intramuscular midazolam effectively control early SE in approximately 63-73 % of patients. Despite a suboptimal safety profile, intravenous phenytoin or phenobarbital are widely used treatments for established SE; alternatives include valproate, levetiracetam, and lacosamide. Anesthetics are widely used in refractory and super-refractory SE, despite the current lack of trials in this field. Data on alternative treatments in the later stages are limited. Valproate and levetiracetam represent safe and effective alternatives to phenobarbital and phenytoin for treatment of established SE persisting despite first-line treatment with benzodiazepines. To date there are no class I data to support recommendations for most antiepileptic drugs for established, refractory, and super-refractory SE. Limiting the methodologic heterogeneity across studies is required and high-class randomized, controlled trials to inform clinicians about the best treatment in established and refractory status are needed.

Levetiracetam versus phenytoin in management of status epilepticus

The purpose of this study was to compare safety and efficacy of intravenous (IV) levetiracetam (LEV) with IV phenytoin (PHT) in management of status epilepticus (SE). The second-line treatment of SE is limited to a few drugs available in an IV formulation such as PHT, fosphenytoin and valproate. The relative lack of serious side effects and favourable pharmacokinetics of LEV made it a promising option in management of SE. Randomized trials comparing relative efficacy of second-line agents are remarkably lacking. In this study, consecutive patients of SE (n=44) were randomized to receive either IV PHT (20mg/kg) or IV LEV (20mg/kg). The primary end point was successful clinical termination of seizure activity within 30min after the beginning of the drug infusion. Secondary end points included recurrence of seizures within 24 hours, drug related adverse effects, neurological outcome at discharge, need for ventilatory assistance, and mortality during hospitalization. Both LEV and PHT were equally effective with regard to primary and secondary outcome measures. PHT achieved control of SE in 15 (68.2%) patients compared to LEV in 13 (59.1%; p=0.53). Both the groups showed comparable results with respect to recurrence of seizures within 24 hours (p=0.34), outcome at discharge as assessed by functional independence measure (p=0.68), need of ventilatory assistance (p=0.47) and death (p=1). From this study it can be concluded that LEV may be an attractive and effective alternative to PHT in management of SE.

Treating Newly Diagnosed Epilepsy: The Canadian Choice

Background:

Choosing an antiepileptic medication to treat a patient with epilepsy can be a complicated process during which the treating physician must base her or his decision on efficacy and safety of each of many available drugs. The lack of comparative studies between medications is one of the reasons.

Methods:

We conducted a survey on the management of newly diagnosed epilepsy in adult patients. The surveyed were adult and pediatric neurologists with a subspecialty interest in epilepsy who were working in academic institutions or private practice across Canada. Scenarios presented were grouped in categories according to the epilepsy syndrome (absence epilepsy, juvenile myoclonic epilepsy, undetermined idiopathic generalized epilepsy, symptomatic or cryptogenic partial epilepsy, and unclassified epilepsy), the patient's gender and age. First and second step in medical treatment for status epilepticus were surveyed as well.

Results:

Forty one of 64 experts responded the survey (responder rate of 66%). The results revealed a consensus among Canadian epileptologists that the first choice of antiepileptic medication in generalized epilepsies was between valproate in men (chosen by 88% of respondents) and lamotrigine in women. In localization-related epilepsies, carbamazepine was the preferred drug of choice (chosen by 90% of respondents). In the treatment of status epilepticus, an initial intravenous dose of lorazepam (95% of respondents), followed by a second dose of lorazepam or intravenous phenytoin in case the initial dose of lorazepam failed, were the treatments preferred.

Management of extravasation injuries: a focused evaluation of noncytotoxic medications

Extravasations are common manifestations of iatrogenic injury that occur in patients requiring intravenous delivery of known vesicants. These injuries can contribute substantially to patient morbidity, cost of therapy, and length of stay. Many different mechanisms are behind the tissue damage during extravasation injuries. In general, extravasations consist of four different subtypes of tissue injury: vasoconstriction, osmotic, pH related, and cytotoxic. Recognition of high-risk patients, appropriate cannulation technique, and monitoring of higher risk materials remain the standard of care for the prevention of extravasation injury. Prompt interdisciplinary action is often necessary for the treatment of extravasation injuries. Knowledge of the mechanism of extravasation-induced tissue injury, agents for reversal, and appropriate nonpharmacologic treatment methods is essential. The best therapeutic agent for treatment of vasopressor extravasation is intradermal phentolamine. Topical vasodilators and intradermal terbutaline may provide relief. Intradermal hyaluronidase has been effective for hyperosmotic extravasations, although its use largely depends on the risk of tissue injury and the severity of extravasation. Among the hyperosmotic agents, calcium extravasation is distinctive because it may present as an acute tissue injury or may possess delayed clinical manifestations. Extravasation of acidic or basic materials can produce significant tissue damage. Phenytoin is the prototypical basic drug that causes a clinical manifestation known as purple glove syndrome (PGS). This syndrome is largely managed through preventive and conservative treatment measures. Promethazine is acidic and can cause a devastating extravasation, particularly if administered inadvertently through the arteriolar route. Systemic heparin therapy remains the accepted treatment option for intraarteriolar administration of promethazine. Overall, the evidence for managing extravasations due to noncytotoxic medications is nonexistent or limited to case reports. More research is needed to improve knowledge of patient risk, prompt recognition of the extravasation, and time course for tissue injury, and to develop prevention and treatment strategies for extravasation injuries.

Efficacy and safety of intravenous valproate for status epilepticus: a systematic review

INTRODUCTION

The effectiveness of valproate (VPA) in the treatment of focal and generalized epilepsies is well established. The drug has a wide spectrum of action, good tolerability, and has been available as an injectable formulation since 1993. Despite the lack of class A evidence, it has been used extensively in various forms of status epilepticus (SE).

AIM

Our aim was to present a systematic review of data from randomized and non-randomized controlled trials to evaluate the efficacy and safety of intravenous VPA for the treatment of SE.

METHODS

Data sources included MEDLINE, back tracing of references in pertinent studies, and contact with the manufacturer of VPA (Sanofi-Aventis).

RESULTS

Overall, the search strategy yielded 433 results (425 MEDLINE, seven congress abstracts, one unpublished study); after excluding duplicate publications and case reports, 30 studies were identified (the earliest was published in 1993, the most recent in 2012); ten were controlled (six randomized controlled trials, four non-randomized controlled studies), and 20 uncontrolled trials (eight prospective observational studies, 12 retrospective case series). The cumulative literature describes the experiences of 860 patients with various forms of SE treated with intravenous VPA. The overall response rate to abrogate SE was 70.9% (601/848; 95% confidence interval [CI] 67.8-73.9). Response rates to intravenous VPA were better in children than in adults and did not differ between the SE types. The most commonly reported effective doses were between 15 and 45 mg/kg in bolus (6 mg/kg/min) followed by 1-3 mg/kg/h infusion. Safety studies of intravenous VPA administration in patients with SE showed a low incidence of adverse events overall (<10%), mainly dizziness, thrombocytopenia, and mild hypotension, which was independent of infusion rates. Of note, good cardiovascular and respiratory tolerability was observed in these studies, even at high doses and fast infusion rates (up to 30 mg/kg at 10 mg/kg/min), despite multiple morbidities or other antiepileptic drugs. The most serious concern relates to the possibility of acute encephalopathy, sometimes related to hepatic abnormalities or hyperammonemia.

CONCLUSIONS

The published experience is consistent with VPA being a safe and effective therapeutic option for patients with established SE who have previously failed conventional first-line treatment with benzodiazepines, but high-quality randomized controlled trials are needed to inform clinicians on its comparative effectiveness in SE.

Status epilepticus: current treatment strategies

Status epilepticus is a neurological emergency that is commonly encountered by the neurohospitalist. Successful treatment depends upon the recognition of prolonged seizure activity and the acute mobilization of available resources. Pharmacologic treatment regimens have been shown to decrease the time needed for successful control of seizures and have provided for the rapid administration of anticonvulsant medications. Treatment strategies have evolved so that clinicians can administer effective doses of medication by whatever routes of administration are immediately available. Traditional algorithms for the treatment of status epilepticus have used a stepwise approach to the administration of first-, second-, and third-order medications. More recent options have included aggressive anesthetic doses of medications while second-line medications are being titrated.

Purple glove syndrome: a dreadful complication of intravenous phenytoin administration

Purple glove syndrome is an uncommon but dreaded complication of intravenous phenytoin administration characterised by pain, oedema and purple-blue discolouration of the limb distal to the site of injection. We describe a 37-year-old gentleman having the characteristic purple glove appearance after phenytoin loading, and discuss the salient features of this syndrome highlighting the pathophysiological and preventive aspects.

An atypical case of purple glove syndrome: an avoidable adverse event

A 73-year-old man presented in status epilepticus. He had a long history of epilepsy for which he was treated with regular phenytoin and phenobarbitone. On admission, his phenytoin level was found to be subtherapeutic and was treated with rectal diazepam and intravenous lorazepam. He was later started on an infusion of phenytoin in preparation to restart his oral medication. The medication was delivered via a peripheral cannula in his forearm. Five days later, he developed redness and swelling of this arm followed by the appearance of a large ulcer. After ruling out infective causes and a compartment syndrome it was felt that the patient had developed a delayed purple glove syndrome secondary to intravenous phenytoin. Following 7 days of regular saline irrigation and dressing changes, the erythema improved and the ulcer showed signs of healing, and eventually resolved.

Levetiracetam versus lorazepam in status epilepticus: a randomized, open labeled pilot study

For the management of status epilepticus (SE), lorazepam (LOR) is recommended as the first and phenytoin or fosphenytoin as the second choice. Both these drugs have significant toxicity. Intravenous levetiracetam (LEV) has become available, but its efficacy and safety has not been reported in comparison to LOR. We report a randomized, open labeled pilot study comparing the efficacy and safety of LEV and LOR in SE. Consecutive patients with convulsive or subtle convulsive SE were randomized to LEV 20 mg/kg IV over 15 min or LOR 0.1 mg/kg over 2-4 min. Failure to control SE within 10 min of administration of one study drug was treated by the other study drug. The primary endpoint was clinical seizure cessation and secondary endpoints were 24 h freedom from seizure, hospital mortality, and adverse events. Our results are based on 79 patients. Both LEV and LOR were equally effective. In the first instance, the SE was controlled by LEV in 76.3% (29/38) and by LOR in 75.6% (31/41) of patients. In those resistant to the above regimen, LEV controlled SE in 70.0% (7/10) and LOR in 88.9% (8/9) patients. The 24-h freedom from seizure was also comparable: by LEV in 79.3% (23/29) and LOR in 67.7% (21/31). LOR was associated with significantly higher need of artificial ventilation and insignificantly higher frequency of hypotension. For the treatment of SE, LEV is an alternative to LOR and may be preferred in patients with respiratory compromise and hypotension.

Recent and future advances in the treatment of status epilepticus

Status epilepticus (SE) is one of the most frequent neurological emergencies with an incidence of 20/100,000 per year and a mortality between 3% and 40% depending on etiology, age, SE type and duration. Generalized convulsive forms of SE (GTCSE), in particular, require aggressive treatment. Presently, only 55-80% of cases of GTCSE are controlled by initial therapy. Therefore, there is a need for new options for the treatment of SE. Here we review the current standard treatment including recent advances and provide a summary of preclinical and clinical data regarding treatment options which may become available in the near future. The initial treatment of SE usually consists of a benzodiazepine (preferably lorazepam 0.1 mg/kg) followed by phenytoin or fosphenytoin or valproic acid (where approved for SE therapy). With intravenous formulations of levetiracetam, available since 2006, and lacosamide, which is expected for autumn of 2008, new treatment options have become available, that should be evaluated in prospective controlled trials. If SE remains refractory, the induction of general anaesthesia using propofol, midazolam, thiopental, or pentobarbital is warranted in GTCSE.

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.

Cost-effectiveness of nonemergency use of phenytoin

Parenteral phenytoin is an effective agent used to manage seizures, but it is associated with adverse effects and must be given intravenously. Fosphenytoin is higher in drug cost, but is more soluble, better tolerated and can be infused at rates three times that of phenytoin. When infusion rate is not an issue the adverse effect risk becomes a focus of concern, as well as cost. The determination of the point at which the treatment costs of infusion-related adverse effects of phenytoin outweigh the drug costs of fosphenytoin has been attempted through various clinical economic analyses. Strategies developed to promote the safe use of intravenous phenytoin are based on patient selection, recommended administration methods and patient monitoring. When rapid attainment of serum phenytoin levels is required or in patients at high risk of adverse effects secondary to parenteral phenytoin, fosphenytoin is clearly preferred. This review will focus on the implications of the use of parenteral phenytoin products in the nonemergent setting where potential adverse effects of parenteral phenytoin may be avoided with use of established criteria for patient selection and administration.

Low-concentration, continuous brachial plexus block in the management of Purple Glove Syndrome: a case report

INTRODUCTION

Purple Glove Syndrome is a devastating complication of intravenous phenytoin administration. Adequate analgesia and preservation of limb movement for physiotherapy are the two essential components of management.

CASE PRESENTATION

A 26-year-old Tamil woman from India developed Purple Glove Syndrome after intravenous administration of phenytoin. She was managed conservatively by limb elevation, physiotherapy and oral antibiotics. A 20G intravenous cannula was inserted into the sheath of her brachial plexus and a continuous infusion of bupivacaine at a low concentration (0.1%) with fentanyl (2 mug/ml) at a rate of 1 to 2 ml/hr was given. She had adequate analgesia with preserved motor function which helped in physiotherapy and functional recovery of the hand in a month.

CONCLUSION

A continuous blockade of the brachial plexus with a low concentration of bupivacaine and fentanyl helps to alleviate the vasospasm and the pain while preserving the motor function for the patient to perform active movements of the finger and hand.

Status epilepticus: a critical review

Status epilepticus (SE) is a major neurological emergency with an incidence of about 20/100,000 and a mortality between 3 and 40% depending on etiology, age, status type, and status duration. Generalized tonic-clonic SE, in particular, requires immediate, aggressive, and effective treatment to stop seizure activity, and to prevent neuronal damage and systemic complications and death. Benzodiazepines and phenytoin/fosphenytoin are traditionally used as first-line drugs and are effective in about 60% of all episodes. However, a notable portion of patients remain in SE. For those, narcotics and induction of general anesthesia are used as second-line treatment. Therefore, there is a need for more effective first-line treatment options. Recently, valproic acid was approved for the treatment of status epilepticus in some European countries, and two of the newer antiepileptic drugs have become available for intravenous use: Levetiracetam (LEV) and lacosamide (LCM) should be evaluated in prospective controlled trials as possible treatment options. Standardized protocols for the management of SE are useful to improve immediate care.

Chemotherapy-induced neuropathy

Neurotoxic side effects of cancer therapy are second in frequency to hematological toxicity. Unlike hematological side effects that can be treated with hematopoietic growth factors, neuropathies cannot be treated and protective treatment strategies have not been effective. For the neurologist, the diagnosis of a toxic neuropathy is primarily based on the case history, the clinical and electrophysiological findings, and knowledge of the pattern of neuropathy associated with specific agents. In most cases, toxic neuropathies are length-dependent, sensory, or sensorimotor neuropathies often associated with pain. The platinum compounds are unique in producing a sensory ganglionopathy. Neurotoxicity is usually dependent on cumulative dose. Severity of neuropathy increases with duration of treatment and progression stops once drug treatment is completed. The platinum compounds are an exception where sensory loss may progress for several months after cessation of treatment ("coasting"). As more effective multiple drug combinations are used, patients will be treated with several neurotoxic drugs. Synergistic neurotoxicity has not been extensively investigated. Pre-existent neuropathy may influence the development of a toxic neuropathy. Underlying inherited or inflammatory neuropathies may predispose patients to developing very severe toxic neuropathies. Other factors such as focal radiotherapy or intrathecal administration may enhance neurotoxicity. The neurologist managing the cancer patient who develops neuropathy must answer a series of important questions as follows: (1) Are the symptoms due to peripheral neuropathy? (2) Is the neuropathy due to the underlying disease or the treatment? (3) Should treatment be modified or stopped because of the neuropathy? (4) What is the best supportive care in terms of pain management or physical therapy for each patient? Prevention of toxic neuropathies is most important. In patients with neuropathy, restorative approaches have not been well established. Symptomatic and other management are necessary to maintain and improve quality of life.

Síndrome da Luva Púrpura: principais intervenções preventivas e terapêuticas de enfermagem

A Síndrome da Luva Púrpura, complicação relacionada à administração de fenitoína por cateteres intravenosos periféricos, caracteriza-se pelo surgimento de lesões teciduais no local de administração do fármaco, que variam de flebite à necrose local, sendo possível se identificar, nos casos mais severos, evolução para a síndrome compartimental e suas graves conseqüências. Este estudo teve por finalidade descrever a Síndrome da Luva Púrpura e os principais cuidados preventivos e terapêuticos de enfermagem. Identificaram-se 15 publicações sobre a temática, das quais incluíram-se dez artigos. Desta forma foi possível verificar as características da síndrome, bem como propor as principais intervenções de enfermagem, tanto na prevenção quanto no cuidado.

Comparative Efficacy and Safety of Antiepileptic Drugs for the Treatment of Status Epilepticus

Status epilepticus (SE) is a medical emergency with high mortality rate. Common causes of SE include noncompliance with antiepileptic medications, drug- and alcohol-related etiologies, and central nervous system (CNS) infections. Because prolonged seizures can cause neuronal damage, treatment should be initiated promptly to avoid potential complications. Previous studies support intravenous (IV) lorazepam as first-line therapy and IV phenytoin or fosphenytoin as a second-line medication. If first-and second-line medications fail to control SE, further treatment with propofol, pentobarbital, midazolam, or other medications should be considered. Many of the drugs currently used to control SE are associated with sedation, respiratory suppression, hypotension, cardiac dysrhythmia, and anaphylactic reactions. Therefore, IV valproate or other newer antiepileptic drugs may be considered as an alternative third-line therapy for those who cannot tolerate the hypotensive effects of other anticonvulsants. This paper reviews comparative effectiveness and safety concerns among frequently used medications for SE.

Phenytoin poisoning

Phenytoin toxicity may result from intentional overdose, dosage adjustments, drug interactions, or alterations in physiology. Intoxication manifests predominantly as nausea, central nervous system dysfunction (particularly confusion, nystagmus, and ataxia), with depressed conscious state, coma, and seizures occurring in more severe cases. Cardiac complications such as arrhythmias and hypotension are rare in cases of phenytoin ingestion, but they may be seen in parenteral administration of phenytoin or fosphenytoin. Deaths are unlikely after phenytoin intoxication alone. A greatly increased half-life in overdose due to zero-order pharmacokinetics can result in a prolonged duration of symptoms and thus prolonged hospitalization with its attendant complications. The mainstay of therapy for a patient with phenytoin intoxication is supportive care. Treatment includes attention to vital functions, management of nausea and vomiting, and prevention of injuries due to confusion and ataxia. There is no antidote, and there is no evidence that any method of gastrointestinal decontamination or enhanced elimination improves outcome. Activated charcoal should be considered if the patient presents early; however, the role of multiple-dose activated charcoal is controversial. Experimental studies have proven increased clearance rates, but this effect has not been translated into clinical benefit. There is no evidence that any invasive method of enhanced elimination (such as plasmapheresis, hemodialysis, or hemoperfusion) provides any benefit. This article provides an overview of phenytoin pharmacokinetics and the clinical manifestations of toxicity, followed by a detailed review of the various treatment modalities.

Fosphenytoin may cause hemodynamically unstable bradydysrhythmias

The prodrug fosphenytoin (FOS) was recently introduced as an alternative to phenytoin (PTN) and has since become a first line therapy for status epilepticus. Unlike PTN, FOS generally has been considered to be safe from cardiac toxicity. To better characterize cardiac toxicity associated with FOS administration, we performed a review of the Food and Drug Administration's Adverse Event Reporting System databank for reports of possible FOS toxicity from 1997-2002. There were 29 applicable reports of adverse cardiac events likely related to FOS infusion, including 10 cardiac deaths. Among survivors, there were four cases of high-grade atrioventricular block, and five cases of transient sinus arrest. Our data suggest that FOS may produce more cardiac toxicity than previously thought. Clinicians should consider administering intravenous FOS in a monitored setting for selected high-risk patients.

Impact of phenytoin therapy on the skin and skin disease

Phenytoin (diphenylhydantoin; Dilantin), ALZA Corp.) is a highly effective and widely prescribed anticonvulsant agent used in the treatment of focal and tonic clonic generalised seizures. The side effects of phenytoin can occassionally engender significant morbidity. Phenytoin can induce generalised eruptions that include: a maculopapular exanthem, Stevens-Johnson syndrome, generalised exfoliative dermatitis, toxic epidermal necrolysis, vasculitis and fixed drug eruptions. Phenytoin is linked to a hypersensitivity syndrome that manifests with fever, rash and lymphadenopathy. Patients receiving phenytoin may develop pseudolymphoma or, rarely, malignant lymphoma and mycosis fungoides-like lesions. Rarer cutaneous side effects include drug-induced lupus, purple hand syndrome, pigmentary alterations and IgA bullous dermatosis. Phenytoin can effect clotting function and alter vitamin and mineral levels. Prenatal exposure to phenytoin may result in a spectrum of structural, developmental and behavioural changes, known as the fetal hydantoin syndrome. Patients who use phenytoin in the long-term commonly manifest with gingival hyperplasia, coarsening of the facies, and hirsutism.

Early histopathologic changes in purple glove syndrome

An 86-year-old African-American man presented with tonic-clonic seizures. Intravenous phenytoin was urgently administered into the dorsum of the right hand. The patient developed a raised purple area of discoloration around the intravenous insertion site within 2 h and edema and vesiculobullous lesions of the distal forearm, hands, and fingers within 8 h. Microscopic sections from a biopsy at 12 h revealed epidermal necrosis, superficial ulceration, and a mild superficial and deep perivascular lymphoid infiltrate, associated with numerous thrombi of small vessels throughout the dermis. The findings were judged to be consistent with soft-tissue injury associated with intravenous administration of phenytoin, also termed purple glove syndrome. Purple glove syndrome, named for its distinctive purple discoloration and swelling of the hands in the distribution of a glove, is an uncommon complication of intravenous phenytoin administration through small dorsal veins of the hands. It is comprised by pain, discoloration, and edema in the vicinity of intravenous infusion of phenytoin through dorsal veins of the hand. The histopathologic features of fully developed lesions have been reported; however, early-stage findings have not been previously described, and the histogenesis of this lesion is controversial. The presence of thrombi in this early-stage lesion suggests that thrombosis plays a role in the initial pathogenesis of this condition.

The treatment of status epilepticus

Status epilepticus (SE) is a life-threatening emergency that requires prompt treatment, including basic neuroresuscitation principles (the ABCs), antiepileptic drugs to stop the seizure, and identification of etiology. Symptomatic SE is more common in younger children. Treating the precipitating cause may prevent ongoing neurologic injury and facilitates seizure control. A systematic treatment regimen, planned in advance, is needed, including one for refractory status epilepticus (RSE). Here we emphasize definitions, clinical and electroencephalography stages, early treatment, special circumstances that may require immediate seizure control, and treatment of RSE. Because much clinical research in SE has been done in adults, we indicate the patient population studied.