New antiepileptic drugs and preparations

An Insight into Molecular Mechanisms and Novel Therapeutic Approaches in Epileptogenesis

Epilepsy is the second most common neurological disease with abnormal neural activity involving the activation of various intracellular signalling transduction mechanisms. The molecular and system biology mechanisms responsible for epileptogenesis are not well defined or understood. Neuroinflammation, neurodegeneration and Epigenetic modification elicit epileptogenesis. The excessive neuronal activities in the brain are associated with neurochemical changes underlying the deleterious consequences of excitotoxicity. The prolonged repetitive excessive neuronal activities extended to brain tissue injury by the activation of microglia regulating abnormal neuroglia remodelling and monocyte infiltration in response to brain lesions inducing axonal sprouting contributing to neurodegeneration. The alteration of various downstream transduction pathways resulted in intracellular stress responses associating endoplasmic reticulum, mitochondrial and lysosomal dysfunction, activation of nucleases, proteases mediated neuronal death. The recently novel pharmacological agents modulate various receptors like mTOR, COX-2, TRK, JAK-STAT, epigenetic modulators and neurosteroids are used for attenuation of epileptogenesis. Whereas the various molecular changes like the mutation of the cell surface, nuclear receptor and ion channels focusing on repetitive episodic seizures have been explored by preclinical and clinical studies. Despite effective pharmacotherapy for epilepsy, the inadequate understanding of precise mechanisms, drug resistance and therapeutic failure are the current fundamental problems in epilepsy. Therefore, the novel pharmacological approaches evaluated for efficacy on experimental models of epilepsy need to be identified and validated. In addition, we need to understand the downstream signalling pathways of new targets for the treatment of epilepsy. This review emphasizes on the current state of novel molecular targets as therapeutic approaches and future directions for the management of epileptogenesis. Novel pharmacological approaches and clinical exploration are essential to make new frontiers in curing epilepsy.

Pharmacotherapy Overview of Seizure Management in the Adult Emergency Department

Seizures are a common cause of emergency department visits, and approximately 28% of epilepsy patients present to an emergency department annually for treatment. This article will provide an overview of the pharmacotherapeutic management of seizures and anticonvulsant therapy for patients who present to the adult emergency department, including practical information for pharmacists covering or cross-covering this practice area. The benzodiazepines are reviewed as a class, including dosing strategies, pharmacodynamic considerations, and advantages and disadvantages of lorazepam, diazepam, and midazolam. Indications for the use of phenytoin and fosphenytoin will be reviewed, as well as dosing, adverse effects, and cost-effectiveness data. In addition, dosing, administration, pharmacokinetics, and adverse effects of phenobarbital, carbamazepine, and valproate will be discussed. Clinical indications for serum anticonvulsant concentration monitoring and subsequent calculation of loading doses from serum concentrations are reviewed. Since status epilepticus is a life-threatening emergency, its therapeutic management is reviewed, including the use of continuous infusion midazolam, pentobarbital, and propofol. There are many opportunities for clinical pharmacists to collaborate with other members of the health care team to optimize efficacy and minimize adverse effects of anticonvulsant agents in the emergency department setting.

Psychiatric medications: adverse cutaneous drug reactions

Psychiatric medications are among the most widely prescribed medications in the United States. Adverse cutaneous drug reactions are associated with psychiatric medications in approximately 2% to 5% of the individuals for whom they are prescribed. Although most adverse cutaneous drug reactions associated with psychotropic medications are benign and easily treated, some can be disfiguring or life-threatening, particularly those associated with the mood stabilizers. Adverse cutaneous drug reactions associated with antidepressants, antipsychotics, and mood stabilizers are reviewed, and important issues that are of concern for the dermatologist who must consider when and how to safely discontinue a psychotropic medication in their patients are presented.

Lamotrigine overdose in a child

The purpose of this article is to describe an unusual presentation of lamotrigine toxicity in an epileptic child treated on a lower than previously reported dosage. This is a case description of a 5-year-old epileptic girl on lamotrigine monotherapy, which caused toxicity. The child presented with ataxia, drowsiness, and acute confusion after ingesting 500 mg (25 mg/kg/d) in two 250-mg doses 12 hours apart. This was followed by vomiting and seizure exacerbation. Discontinuing lamotrigine, intravenous fluids and observation were the mainstays of therapy. Until now, the reported minimum dose of lamotrigine causing toxicity was 800 mg. In this patient, toxic manifestation occurred after the initial 250 mg. This case report demonstrates the low safety margin in children treated with lamotrigine.

Pediatric ingestion of lamotrigine

A 3-year-old female presented to the emergency department after ingesting forty-six 25-mg tablets of lamotrigine that resulted in sedation, rash, and transient elevation of liver function tests. Her initial physical examination was significant for marked somnolence and a lacy reticular blanching rash. Laboratory studies were all within normal limits except for mildly elevated liver function tests. Initial plasma lamotrigine level was found to be elevated above adult therapeutic levels (25.3 microg/mL). Treatment consisted of gastric lavage followed by activated charcoal. The patient was subsequently observed in the pediatric intensive care unit where symptoms and laboratory abnormalities promptly resolved, and she was discharged 24 hours later without further complication. This case report describes the largest single ingestion of lamotrigine ever reported in a pediatric patient. The patient exhibited significant somnolence, rash, and liver function test abnormalities with only a slight elevation of serum level of lamotrigine above adult therapeutic levels. More research is required to investigate the toxic profile of lamotrigine in pediatric patients.

Adverse cutaneous reactions to mood stabilizers

Of all the psychotropic medications currently available, the mood-stabilizing agents have the highest incidence of severe and life-threatening adverse cutaneous drug reactions (ACDRs). An exanthematous eruption in a patient treated with a mood-stabilizing agent should be viewed as possibly being the initial symptom of a severe and life-threatening ACDR, such as a hypersensitivity reaction, Stevens-Johnson syndrome, or toxic epidermal necrolysis. The combination of mood-stabilizing agents may increase the risk of such reactions. The mood-stabilizing agents addressed in this article are carbamazepine, lithium carbonate, valproic acid, topiramate, lamotrigine, gabapentin, and oxcarbazepine. Prior to the initiation of a mood stabilizer, the potential benefits, risks, and adverse effects should be communicated to the patient. If possible, slow dose escalation should be attempted by the physician. Patients should also be advised to seek medical attention if they suspect a drug-induced skin reaction. If the physician suspects a severe ACDR, the offending agent should be removed immediately.