Lamotrigine-induced Stevens-Johnson syndrome: demonstration of specific lymphocyte reactivity in vitro

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.

In vitro release of interferon-gamma from peripheral blood lymphocytes in cutaneous adverse drug reactions

BACKGROUND

Cutaneous drug reactions are common but diagnostically challenging due to phenotypic heterogeneity and simultaneous exposure to multiple drugs. These limitations prompted the development of diagnostic tests.

AIMS

To evaluate the performance of an in vitro assay measuring interferon-gamma release from patients' lymphocytes in the presence of causative drugs for the diagnosis of drug reactions.

METHODS

Mononuclear cells derived from patients were incubated with and without suspected drugs, and increment of interferon-gamma levels was measured by ELISA. We performed a telephonic survey to evaluate the effect of stopping the drugs incriminated by the assay on cutaneous manifestations.

RESULTS

We assessed 272 patients who used 1035 medications. When assessed against the questionnaire data collected at least 6 months after stopping the causative drug, sensitivity was found to be 83.61% and specificity 92.67%. Likelihood ratio for a positive test is 11.40 and for a negative test 0.18. Positive predictive value is 75.37% and negative predictive value is 95.47%. The test was found to perform significantly better in females and in older patients.

CONCLUSIONS

Interferon-gamma release test is a useful adjunct tool in the diagnosis of cutaneous drug reactions.

Poor relevance of a lymphocyte proliferation assay in lamotrigine-induced Stevens-Johnson syndrome or toxic epidermal necrolysis

BACKGROUND

Prior use of 'lymphocyte transformation test' (LTT) in Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) provided conflicting results, possibly dependent on sampling dates (acute vs. late).

OBJECTIVE

Evaluation of LTT in patients with SJS or TEN who reacted to lamotrigine (LTG). In a small subgroup we explored the possible role of regulatory T cells (T-reg).

METHODS

Acute phase samples (9) and post-recovery samples (14) from cases of SJS or TEN to LTG were provided by the RegiSCAR-study group. Controls were persons never exposed to LTG (12), patients exposed without reaction (6), and patients who developed a mild eruption to LTG (6). LTT was performed by measuring (3) H-thymidine incorporation after 3 days of incubation with phytohemmaglutinin, LTG (10 μg/mL) or medium. Stimulation index ≥ 2 was considered positive. In 16 cases LTT was redone after depletion of T-reg by fluorescence activated cell sorting.

RESULTS

Positive LTT was observed in 3/6 cases of mild eruptions, 1/9 SJS/TEN-cases tested during the acute phase and 3/14 SJS/TEN-cases tested after recovery. We noted a very mild and nonsignificant trend for an increased response after depletion of T-reg in late samples from SJS or TEN patients.

CONCLUSIONS AND CLINICAL RELEVANCE

With the largest number of LTT performed in patients with SJS or TEN to a single drug, we confirmed that reactive cells are rarely detected in these reactions. Poor reactivity did not seem related to T-reg. Other in vitro assays than those testing proliferation should be evaluated, before raising the hypothesis that specific cells disappeared by undergoing apoptosis during the reaction.

Lamotrigine-induced toxic epidermal necrolysis in a young epileptic

A 20-year-old young female presented with extensive skin rashes with bullae and extensive epidermal necrolysis about 20 days after the addition of lamotrigine (LTG) to her anticonvulsant medication. The patient was managed by stopping LTG and supportive treatment. The seizures were controlled with increase in the doses of carbamazepine. The report emphasises exercising of caution once LTG is added to a regimen containing valproic acid.

[Difficulties in detecting the causative agent of an adverse drug reaction in a complicated case]

Due to the great variety of drug-induced adverse side-effects, the causative agent could not be easily determined. Improvement of the clinical picture after cessation of the causative agent, the clinical observations, as well as data given in medical literature might provide useful information for the imputability of a drug. The diagnosis of drug hypersensitivity is difficult, and must be carefully considered. It is needed in cases when the causative agent cannot be replaced by another in the same pharmacological family of the drug and when the patient is in absolute need of the medicine. The aim of this article is to emphasize the required possibilities and arising dangers in the check-up of the patient. In the investigation process at the hospital: a patch test was applied with the possible causative agents: lamotrigine, risperidone, sertraline, zopiclone, atorvastatin. It was sertraline that proved to be positive. Histologic examination taken from the site of positive drug-patch test referred to the original form of the drug-induced adverse side-effect (erythema exsudativum multiforme). Because of the bipolar affective disorder of the patient we executed oral rechallenge of the patient with the cutaneous negative culprit drugs. Oral rechallenge, in spite of being hazardous for the patient, is the only reliable method for detecting the causative agent. However, by the rechallenge with the drugs, even a partial dose of lamotrigine proved to be positive, after 3 hours erythema occurred, and 12 hours later scarlatiniform exanthema developed in spite of intravenous administration of steroid and antihistamine medication. The case's curiosity is that one causative agent proved to be positive by epicutaneous patch test meanwhile another drug was positive by the oral rechallenge. Finally, in spite of being consistent with the clinical picture, only one certain method cannot be totally sufficient and reliable in the investigation process of eliciting the causative agent in patients with adverse drug reactions.

Phenytoin desensitization monitored by antigen specific T cell response using carboxyfluorescein succinimidyl ester dilution assay

We evaluated drug-specific T cell responses in a patient with refractory partial seizures and paroxysmal kinesigenic choreoathetosis successfully treated with clinical desensitization to phenytoin. Drug-induced lymphocyte transformation test before desensitization was negative with a stimulation index of 130%. The frequencies and cytokine-producing phenotypes of phenytoin-specific T cells were examined simultaneously by using a carboxyfluorescein succinimidyl ester (CFSE) dilution assay. Before desensitization, the proportion of CFSElow CD4+ cells in whole CD4+ was 3.09%; 13.6% of CFSElow CD4+ cells were stained with anti-interferon gamma antibody. After desensitization, phenytoin-specific CFSElow CD4+ cells decreased to background level. These results indicate that CFSE dilution assay will be useful for the diagnosis and monitoring of drug hypersensitivity.

Phenytoin desensitization in a child with symptomatic localization-related epilepsy

We reported a child with refractory partial seizures successfully managed by clinical desensitization to phenytoin. The patient had ischemic brain lesions due to cardiopulmonary arrest at 39 weeks of corrected age. He had complex partial seizures refractory to several antiepileptic drugs since 4 years of age. At 8 years 1 month of age, phenytoin was first administered. Fever and maculopapular rashes appeared at 10 days after phenytoin initiation, and then the drug was discontinued. At 8 years 8 months of age, desensitization was attempted because of refractoriness of seizures to drugs other than phenytoin. Desensitization was started at 1mg daily, and then the dose was doubled every week. His seizures were controlled by 150mg/day of phenytoin in combination with primidone. No problems have been observed during desensitization.

Toxic epidermal necrolysis

Toxic epidermal necrolysis (TEN) is an unpredictable, life-threatening drug reaction associated with a 30% mortality. Massive keratinocyte apoptosis is the hallmark of TEN. Cytotoxic T lymphocytes appear to be the main effector cells and there is experimental evidence for involvement of both the Fas-Fas ligand and perforin/granzyme pathways. Optimal treatment for these patients remains to be clarified. Discontinuation of the offending drug and prompt referral to a burn unit are generally agreed upon steps. Beyond that, however, considerable controversy exists. Evidence both pro and con exists for the use of IVIG, systemic corticosteroid, and other measures. There is also evidence suggesting that combination therapies may be of value. All the clinical data, however, is anecdotal or based on observational or retrospective studies. Definitive answers are not yet available. Given the rarity of TEN and the large number of patients required for a study to be statistically meaningful, placebo controlled trials are logistically difficult to accomplish. The absence of an animal model further hampers research into this condition. This article reviews recent data concerning clinical presentation, pathogenesis and treatment of TEN.

LEARNING OBJECTIVES

At the conclusion of this learning activity, participants should have acquired a more comprehensive knowledge of our current understanding of the classification, clinical presentation, etiology, pathophysiology, prognosis, and treatment of TEN.

Stevens-Johnson syndrome due to concomitant use of lamotrigine and valproic acid

Stevens-Johnson syndrome (SJS) is a rare but life-threatening acute mucocutaneous hypersensitivity reaction, usually related to drugs. Severe cutaneous adverse effects such as SJS and toxic epidermal necrolysis can arise during treatment with antiepileptic drugs (AEDs). A 23-year-old female patient with idiopathic epilepsy was referred to the emergency service with fever, oral and genital mucosal lesions, generalized rash, and weakness. She had been taking carbamazepine, valproic acid, and lamotrigine until 1 week prior to referral. Following consultations with a range of clinicians, the patient was diagnosed with SJS related to lamotrigine on the basis of her history and physical findings, and on consideration of current consensus definitions of this condition. The patient was followed up and treated in the emergency intensive care unit with intravenous fluids, antibacterial therapy, and methylprednisolone. After 18 days, the patient was considered to have made a sufficient recovery and was discharged. Patients who undergo therapy with AEDs, particularly new users of these agents, should be informed of and monitored for possible systemic and cutaneous adverse effects of AEDs. Polytherapy should be avoided for as long as possible as this increases the frequency of adverse effects, and treatment should be discontinued if any rash appears.

Treatment of acute mania--from clinical trials to recommendations for clinical practice

No consensus has been reached with regard to the treatment of bouts of acute mania in various parts of the world. Controlled clinical trials have, at last, provided irrefutable evidence of the activity of lithium, which has long been used alone, as well as that of divalproate or its derivatives and, to a lesser extent, carbamazepine. The new antipsychotic agents have more recently established their efficacy, especially olanzapine, risperidone and aripiprazole. It is paradoxical to note that, in Europe, haloperidol is still the reference substance used in clinical trials despite the fact that it is not officially indicated in the treatment of mania. In the USA, lithium, divalproate or antipsychotics can be prescribed as first-line treatment. In Europe, lithium remains the first-line medication, whereas divalproate and atypical antipsychotic agents are used only as second-line therapy. The conventional antipsychotic agents (such as haloperidol, loxapine or zuclopenthixol) which should no longer be prescribed during manic episodes given the potential risks and side effects associated with these substances (extrapyramidal side effects, depressogenic effect, malignant syndrome) are still prescribed extensively in Europe. Although both types of medication (antipsychotics, normothymic agents and/or anticonvulsants) have proved to be clinically effective in the management of mania by reducing the mania scores overall, the same does not apply, however, to all symptoms of mania. Factorial approaches to mania have all shown that since there are several clinical forms of mania, several lines of manic symptoms can be identified. Antipsychotic and normothymic agents and/or anticonvulsants do not appear to have the same effects on each of these identifiable clusters of symptoms, mainly psychotic features. We believe that it is vitally important for future clinical trials of mania treatment to focus on the treatment effect by adopting a factorial approach to the episode with an appropriate methodological structure provided to this end. These questions highlight the uncertainty shrouding the very structure of manic episodes, namely that these are predominantly of a thymic or psychotic nature. The Europeans undoubtedly consider mania to be more of a thymic episode and prefer lithium as the first-line treatment, whereas the Americans believe that psychotic symptoms dominate and widely prescribe antipsychotic agents. However, from the standpoint of clinical trials currently available, even though antipsychotic agents are certainly effective in reducing the scores on the mania scales, can they be considered purely as antimania treatments?

Drug hypersensitivity reactions in skin: understanding mechanisms and the development of diagnostic and predictive tests

Cutaneous manifestations of drug hypersensitivity can be serious and potentially life threatening and may prevent effective drug therapy. T cells play an important role in the pathology of drug hypersensitivity reactions. Classical studies suggest that T-cell activation requires drug bioactivation, covalent binding to protein and antigen processing to stimulate an immune response. Recent studies have shown that drugs can also be presented to T cells in the absence of antigen processing and drug metabolism. In this article, sulfamethoxazole is used as a paradigm to describe the chemical mechanisms involved in the initiation and maintenance of an aberrant drug antigen specific T-cell response. Presentation of the same drug to different individuals can cause a variety of skin diseases. Such reactions have been classified according to the phenotype and functionality of the T-cell response. This review summarises the different forms of cutaneous hypersensitivity reactions and describes how T-cell clones generated from hypersensitive patients have been used to study the cellular mechanisms of anticonvulsant hypersensitivity. Potential uses of in vitro cell culture assays for patient diagnosis and drug evaluation are also discussed.

Characterization of drug-specific T cells in lamotrigine hypersensitivity

BACKGROUND

Lamotrigine is associated with hypersensitivity reactions, which are most commonly characterized by skin rash. An immune etiology has been postulated, though the nature of this is unclear.

OBJECTIVES

The aim of this study was to characterize the role of T cells in lamotrigine hypersensitivity.

METHODS

A lymphocyte transformation test was performed on 4 hypersensitive patients. Lymphocytes from 3 of 4 lamotrigine-hypersensitive patients proliferated when stimulated with lamotrigine. T-cell clones were generated from one patient to further characterize the nature of the T-cell involvement. Cells were characterized in terms of their phenotype, functionality, and mechanisms of antigen presentation and cytotoxicity.

RESULTS

Of the 44 drug-specific T-cell clones generated, most were CD4(+) with occasional CD8(+) cells. All clones expressed the alphabeta T-cell receptor; several Vbeta 5.1(+) or 9(+) T-cell clones were generated. All clones also expressed the skin-homing receptor cutaneous lymphocyte antigen. Lamotrigine-stimulated T cells were cytotoxic and secreted perforin, IFN-gamma, IL-5, and macrophage inflammatory protein 1alpha, macrophage inflammatory protein 1beta, RANTES, and I-309. Lamotrigine was present on HLA-DR and HLA-DQ by antigen-presenting cells in the absence of drug metabolism and processing. The T-cell receptor of certain clones could accommodate analogs of lamotrigine, but no cross-reactivity was seen with other anticonvulsants.

CONCLUSIONS

Our data provide evidence that T cells are involved in the pathogenesis of some lamotrigine-hypersensitivity reactions. The identification of drug-specific cells that express cutaneous lymphocyte antigen and type 1 cytokines after T-cell receptor activation is consistent with the clinical symptoms. Furthermore, identification of large numbers of Vbeta 5.1(+) T cells suggests that polymorphisms within T-cell receptor genes might act as determinants of susceptibility.

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.

Anticonvulsant hypersensitivity syndrome in children: incidence, prevention and management

Anticonvulsant hypersensitivity syndrome (AHS) is a rare, but potentially fatal, adverse reaction that occurs in patients, including children, who are treated with anticonvulsants. During metabolism of the anticonvulsant, toxic arene-oxide compounds are produced. AHS is associated with both cutaneous and systemic symptoms and is associated with multiorgan involvement. Liver damage, in particular, seems to be associated with fatal outcomes. The pathophysiology of AHS is still uncertain but it may be linked to a genetically determined inability to detoxify reactive drug metabolites. The prompt recognition of the first clinical signs of AHS, and the rapid withdrawal of the anticonvulsant, often avoids the progression of symptoms. Pharmacological treatment is essentially based on systemic corticosteroids in association with enteral nutrition, intravenous fluid augmentation, pain relief and ocular care. Intravenous immunoglobulins may also have a possible therapeutic role in some cases. Diagnostic tests, such as patch tests or in vitro assays, for AHS could help to identify patients at risk of developing the syndrome and could represent a first step of primary prevention when applied to relatives of patients.

Valproate-associated stomatitis

The purpose of this article is to report a case of severe stomatitis in a patient with pediatric epilepsy taking divalproex sodium. The case was reviewed with detailed oral examinations. This 5-year-old child developed severe stomatitis 18 months after institution of divalproex sodium. Cessation of the medication was associated with resolution of the stomatitis. A review of the pertinent literature is also provided. Stomatitis is a rare but potentially serious adverse effect of divalproex sodium administration.

Life-threatening adverse events of antiepileptic drugs

Treating a patient with antiepileptic drugs (AEDs) may give rise to unexpected life-threatening adverse events. Despite extensive experimental and clinical testing to ensure safety, most AEDs on the market have been associated with cases of severe cutaneous reactions, serious hematological disorders, or hepatic failure. Most of these disorders emerge as idiosyncratic immune-mediated disease or are related to toxic metabolic products of the AEDs. Early diagnosis is the only means of reducing the harmful, potentially fatal effects of these reactions. A high degree of suspicion, knowledge of risk factors, and close physician-patient contact increases the likelihood of early diagnosis and treatment. When diagnosed, severe reactions must be fully documented and reported to health authorities. The very rare occurrence of life threatening events should not, in general, limit treatment decision-making. Future epidemiological, chemical, and genetic research might provide methods for ascertaining which patients are at risk, so undue exposure can be avoided.

Metabolic activation in drug allergies

Drug allergies are a major problem in the clinic and during drug development. At the present time, it is not possible to predict the potential of a new chemical entity to produce an allergic reaction (hypersensitivity) in patients in preclinical development. Such adverse reactions, because of their idiosyncratic nature, only become apparent once the drug has been licensed. Our present chemical understanding of drug hypersensitivity is based on the hapten hypothesis, in which covalent binding of the drug (metabolite) plays a central role in drug immunogenicity and antigenicity. If this theory is correct, then it should be possible to develop in vitro systems to assess the potential of drugs to bind to critical proteins, either directly or indirectly after metabolic activation to protein-reactive metabolites (bioactivation) and initiate hypersensitivity. The purpose of this review is to assess critically the evidence to support the hapten mechanism, and also to consider alternative mechanisms by which drugs cause idiosyncratic toxicity.

Immunological principles of adverse drug reactions: the initiation and propagation of immune responses elicited by drug treatment

Adverse drug reactions account for between 2 to 5% of all hospital admissions and can prevent the administration of an otherwise effective therapeutic agent. Hypersensitivity or immune-mediated reactions, although less common, tend to be proportionately more serious. There is convincing evidence to implicate the immune system in the pathogenesis of hypersensitivity reactions. Our understanding of the way in which the immune system recognises drugs is based on the hapten hypothesis; the onset of hypersensitivity involves drug bioactivation, covalent binding to proteins, followed by uptake, antigen processing and T cell proliferation. Central to this hypothesis is the critical role of drug metabolism, with the balance between metabolic bioactivation and detoxification being one important component of individual susceptibility. The purpose of this review is to classify drug hypersensitivity reactions in terms of their clinical presentation, and also to consider recent advances in our understanding of the chemical, biochemical and, in particular, cellular immunological mechanisms of hypersensitivity. The following topics are reviewed: (i) drug disposition and cellular metabolism; (ii) mechanisms of antigen processing and presentation; (iii) the role of cytokines and co-stimulatory molecules in the induction and maintenance of a polarised immune response; and (iv) the application of the hapten hypothesis, danger hypothesis and serial triggering model to drug hypersensitivity. A greater understanding of the mechanism(s) of hypersensitivity may identify novel therapeutic strategies and help to combat one of the more severe forms of adverse reactions to drugs.

Advances in molecular toxicology-towards understanding idiosyncratic drug toxicity

Idiosyncratic drug toxicity is a major complication of drug therapy and drug development. Such adverse drug reactions (ADRs) include anaphylaxis, blood dyscrasias, hepatotoxicity and severe cutaneous reactions. They are usually serious and can be fatal. At present, prediction of idiosyncratic ADRs at the preclinical stage of drug development is not possible because there are no suitable animal models and we do not understand the basic mechanisms involved in the toxicity when it does occur in man. Many idiosyncratic reactions appear to have an immunological aetiology. For example, there is increasing evidence for the role of T lymphocytes in severe skin reactions. Nevertheless, the sequence of events by which a simple chemical can elicit severe tissue damage remains poorly understood and alternative novel mechanisms of toxicity must also be explored. The purpose of this article will be to review the currently accepted mechanisms of idiosyncratic drug toxicity at the chemical and the molecular levels. In particular, we will consider how recent advances in cellular immunology and molecular biology can improve our understanding of both the chemical and clinical aspects of drug hypersensitivity. Recent advances in the role of both inter- and intra-cellular signalling in the regulation of the immune response to drugs and their metabolites will be discussed. The long-term aim of such research is to provide test systems for the evaluation of drug safety and patient susceptibility to idiosyncratic drug toxicity.

Acute granulomatous interstitial nephritis and colitis in anticonvulsant hypersensitivity syndrome associated with lamotrigine treatment

We present the case of a 17-year-old woman with a history of bipolar disorder, who developed a clinical syndrome manifested by fever, lymphadenopathy, skin rash, diarrhea, and acute renal failure requiring dialysis after the use of lamotrigine. Renal biopsy showed acute interstitial nephritis (AIN) with focal granulomas. Similarly, colonic biopsy specimens showed colitis and ileitis with non-necrotizing epithelioid granulomas. The patient had a complete recovery after withdrawal of the medication and steroid treatment. Although lamotrigine has been previously implicated in the development of anticonvulsant hypersensitivity syndrome, there have been no previous reports of acute granulomatous interstitial nephritis or colitis associated with the use of this drug.

Pharmacotherapy of depression and mixed states in bipolar disorder

The treatment of bipolar depression requires the resolution of depression and the establishment of mood stability. A basic problem is that the treatments used in treating bipolar depression were developed and proven effective for other disease states: antidepressants for unipolar depression, and mood stabilizers for mania. The panel addressed four unresolved questions regarding depression in relation to bipolar disorder: (1) the relative effectiveness of different antidepressant treatments; (2) the relative likelihood of mood destabilization with different antidepressant treatments; (3) the effectiveness and role of mood-stabilizing medicines as antidepressants; and (4) the optimal approach to mixed states. The selection of an antidepressant depends both on its relative lack of mania- or hypomania-provoking potential and on its effectiveness against bipolar depression. There is little definitive evidence distinguishing effectiveness of the major groups of antidepressive agents, so side-effect profiles and pharmacokinetics are major considerations. The underlying bipolar disorder should be treated with mood stabilizers started simultaneously with any antidepressive treatments. Lithium, divalproex sodium and carbamazepine have all been found to be helpful, to some extent, in treating bipolar depressive episodes as well as for long-term mood stabilization. There is little evidence for long-term benefits of antidepressive agents in bipolar disorder, and some evidence that they may destabilize the disorder. Therefore, in contrast to the long-term use of mood-stabilizers, antidepressant use is recommended on a temporary basis. The duration of antidepressant treatment is determined by past history in terms of liability for mood destabilization, and by the ability of the patient to tolerate gradual antidepressant discontinuation without return of depression. Mixed states, where symptoms of depression and mania coexist, are regarded as a predictor of relatively poor response to lithium, and divalproex has been found to be more effective. Carbamazepine may too be useful in mixed states. Most patients with mixed states in actual practice require combinations of mood stabilizers, though there is little controlled data regarding such co-prescription, especially from a long-term perspective.

Severe hypersensitivity syndrome to lamotrigine confirmed by lymphocyte stimulation in vitro

BACKGROUND

The anticonvulsant lamotrigine has been associated with severe adverse events such as the hypersensitivity syndrome and severe bullous reactions. So far, specific immunologic tests have rarely been performed to demonstrate specific sensitization.

METHODS

A 36-year-old man suffering from epilepsy was concomitantly treated with high doses of sodium valproate and lamotrigine. About 1 month later, a severe hypersensitivity syndrome occurred affecting skin, lymph nodes, and liver. Three months later, skin tests and lymphocyte stimulation tests with anticonvulsants were performed.

RESULTS

Skin tests were negative with all drugs; lymphocyte stimulation tests were twice positive with lamotrigine. Later re-exposure to sodium valproate was tolerated.

CONCLUSIONS

Lamotrigine may elicit a severe hypersensitivity syndrome. Particularly high initial doses and concomitant treatment with sodium valproate increase the risk of cutaneous reactions. The lymphocyte stimulation test was used to identify the culprit drug. Lymphocyte sensitization to the drug or a metabolite may be involved in the pathogenesis.

The diagnostic role of the in vitro drug-induced interferon-gamma release test in Stevens-Johnson syndrome

BACKGROUND

Drug-related T-cell activity in cutaneous drug reactions may be assessed by in vitro cytokine release tests. The diagnostic role of in vitro drug-induced interferon-gamma (IFN-gamma) release was evaluated in a patient with Stevens-Johnson syndrome.

CASE REPORT

Stevens-Johnson syndrome was diagnosed in a 58-year-old man, treated with colchicine (1 mg daily for 39 days) and allopurinol (300 mg daily for 13 days). Based on a clinical-epidemiologic score, allopurinol was more likely to be the causative agent. In vitro drug-induced IFN-gamma release test was conducted on this patient and on two controls, using an enzyme-linked immunoabsorbent assay (ELISA) technique. Increased IFN-gamma release was observed following an in vitro challenge of the patient's lymphocytes with allopurinol, but not following in vitro challenge with colchicine. An in vitro challenge with allopurinol in two control patients, treated with allopurinol without adverse drug reactions, did not induce a significant increase in IFN-gamma release.

CONCLUSIONS

The role of allopurinol as the drug responsible for the induction of Stevens-Johnson syndrome in our patient was confirmed by in vitro allopurinol-induced IFN-gamma release, which may indicate a drug-specific immune response.

Lamotrigine-associated rash: risk/benefit considerations in adults and children

PURPOSE

Lamotrigine (LTG) is an antiepileptic drug (AED) recently released in several countries. It is effective for a variety of seizure types in adults and children both as an add-on agent and in monotherapy, and is generally well tolerated. This report reviews the apparent risk factors for rash associated with LTG to determine whether and how the risk of serious rash can be minimized in practice.

METHODS

The panel of experts reviewed all published and unpublished data related to the incidence and risk factors for serious rash with LTG.

RESULTS

An allergic skin reaction occurs in approximately 10% of patients, usually in the first 8 weeks. Rashes leading to hospitalization, including Stevens-Johnson syndrome and hypersensitivity syndrome, occurred in approximately one of 300 adults and one of 100 children in clinical trials and appeared to be increased with overrapid titration when starting therapy and with concurrent valproate (VPA).

CONCLUSIONS

Recommendations are made for both minimizing the likelihood of serious rash and for management of rash in patients taking LTG. Risk of serious rash may possibly be lessened by strict adherence to manufacturer's dosing guidelines, particularly in patients who are at higher risk: those on concurrent VPA and in the pediatric population.

Hypersensitivity reaction in a child due to lamotrigine

Lamotrigine is an anticonvulsant with a broad spectrum of activity that has been approved in the United States for use in adults with either partial or generalized seizures. This drug is being widely prescribed by pediatricians and neurologists because it is effective in children with idiopathic, resistant, generalized seizures and does not impair cognition. As with other anticonvulsants, a hypersensitivity syndrome has been described. Anticonvulsant hypersensitivity syndrome consists of the hallmark features of fever, rash, and lymphadenopathy. We report the first case of hypersensitivity syndrome in a child due to lamotrigine in which we believe the coadministration of valproic acid increased the duration of the reaction. Our patient had a high spiking fever, generalized morbilliform eruption, facial edema, lymphadenopathy, eosinophilia, atypical lymphocytosis, and an elevation in his liver function tests. The syndrome resolved with the discontinuation of the medication. Anticonvulsant hypersensitivity syndrome may occur with the administration of lamotrigine. Variable presentations may be seen, as hypersensitivity syndromes may be multisystem in nature. The prompt recognition of the signs and symptoms of this condition allows an accurate diagnosis so that the drug may be discontinued and other anticonvulsant treatment options instituted.

Lamotrigine-induced severe cutaneous adverse reactions

PURPOSE

We systematically reviewed and analyzed published and unpublished cases of Stevens-Johnson syndrome (SJS), or toxic epidermal necrolysis (TEN) associated with lamotrigine (LTG) therapy to identify characteristics of these reactions.

METHODS

We performed a MEDLINE search (January 1985 to April 1998) and citation tracking for published reports. In addition, reports were requested from the Uppsala Monitoring Centre of the World Health Organization (WHO). Published and WHO cases of LTG-associated SJS or TEN were included if the causal relationship was assessed as either possible, probable, or definite.

RESULTS

We identified a total of 57 cases (43 cases of SJS, 14 cases of TEN), of which 13 (23%) were published. Cases in the SJS group were significantly younger than in the TEN group (21 years vs. 31 years). The median time to onset (17 days for SJS and TEN) and the median dosage at onset (50 mg vs. 87.5 mg) for SJS and TEN did not differ significantly. Concomitant use of valproate (VPA) was reported in 74% of the SJS cases and 64% of the TEN cases. In three cases, TEN was the cutaneous manifestation of the antiepileptic drug hypersensitivity syndrome (AHS).

CONCLUSIONS

The main features of severe cutaneous drug reactions, such as dosage, onset, and concomitant VPA use, do not differ in patients with LTG-induced SJS or TEN. SJS or TEN may also be the cutaneous manifestations of LTG-induced AHS. Further epidemiologic studies are needed to identify the incidence of severe LTG-induced cutaneous adverse reactions and the relative risk compared with other AEDs.

Quantifying the costs of serious adverse drug reactions to antiepileptic drugs

PURPOSE

We assessed from an institutional perspective the direct costs of severe adverse cutaneous or hypersensitivity reactions due to antiepileptic drug (AED) therapy that led to hospitalization or prolonged hospital stay.

METHODS

Patients admitted for or developing severe AED-induced cutaneous or hypersensitivity reactions while in hospital from January 1990 through June 1996 were identified by ICD-9 codes E936, E937, E693, E695.1, E995.1, and E995.2. Identified cases were analyzed retrospectively by chart review and were included in the analysis if a causal relationship was determined to be possible, probable, or definite. Clinical outcomes were abstracted and related direct costs of the adverse drug reactions (ADRs) calculated.

RESULTS

A total of 384 cases were identified by ICD-9 codes, of which 13 cases (mean age +/- SD 52.9+/-21.0 years) were included for further analysis. Eight patients (62%) were admitted because of an ADR (median length of stay 9.5 days; range 4-43), five (38%) experienced an ADR during hospitalization (median duration of ADR episodes 8.5 days; range: 7-21 days). The median direct medical costs of the ADRs were Canadian (CDN) $3,128 (range 1,149-21,293) per patient.

CONCLUSIONS

The management of serious cutaneous and hypersensitivity ADRs due to AEDs is associated with considerable direct medical costs. These figures should be considered along with drug acquisition costs and treatment of clinical successes and failures in the overall assessment of the economic impact of pharmacotherapy. Prospective collection of direct costs associated with ADRs in clinical trials would be of value.

New drugs for epilepsy

Seizure freedom with no side-effects is the aim of treatment, and new antiepileptic drugs have not lived up to expectations; only a few patients with chronic epilepsy have been rendered seizure-free. These treatments have side-effects but their safety profile may be better than older alternatives, although chronic effects have not yet been established. This article reviews newly marketed antiepileptic drugs. It concentrates on shortcomings of current antiepileptic treatment and on the way drugs are developed. A new approach to treatment is long overdue. The development of rational antiepileptic treatments should be strongly encouraged. More clinically relevant paradigms need to be developed and incorporated into clinical trial programmes as these are presently biased in their designs towards regulatory issues.