Lamotrigine and toxic epidermal necrolysis

Tolerated drugs in subjects with severe cutaneous adverse reactions (SCARs) induced by anticonvulsants and review of the literature

Background

Anticonvulsant hypersensitivity syndrome represents a rare but potentially fatal kind of adverse drug reaction. This clinical picture often hampers the flexibility with which alternative anticonvulsants or even other classes of drugs are prescribed in these patients, negatively affecting the efficacy of treatment and the course of the disease. The aim of this study was to analyse a group of six patients with severe cutaneous drug reactions induced by anticonvulsants and to report which alternative antiepileptic drugs and which drugs of other classes were tolerated.

Case presentation

A total of six patients (2 males and 4 females, age 11–73 years) are described in this study. In all the patients the onset of the severe cutaneous drug reactions was 2–4 weeks after initiating the anticonvulsant therapy: 2 out of 6 patients presented with a drug reaction with eosinophilia and systemic symptoms under therapy with phenytoin; 2 out of 6 presented with Stevens–Johnson syndrome under therapy with lamotrigine; and 2 out of 6 presented with a toxic epidermal necrolysis, one of them under therapy with valproic acid, and the other one under therapy with lamotrigine. Alternative anticonvulsants tolerated after the reaction were: clonazepam, levetiracetam, diazepam, delorazepam and lormetazepam.

Conclusions

In our cases we observed that non aromatic anticonvulsants and benzodiazepines were well tolerated as alternative treatments in six patients with reactions to aromatic anticonvulsivants and that the risk of hypersensitivity reactions to other drug classes was not increased as compared to general population.

Protein-functionalized PLGA nanoparticles of lamotrigine for neuropathic pain management

Lamotrigine (LTG), a sodium and calcium channel blocker, has demonstrated efficacy for the treatment of neuropathic pain in multiple, randomized, controlled trials. However, its potential clinical applications in neuropathic pain are limited due to the risk of dose-dependent severe rashes associated with high dose and prompt dose escalation. Further, the poor pharmacokinetic profile due to non-selective distribution to organs other than brain reduces the efficacy of dosage regimen. Therefore, the aim of present investigation is to develop surface-engineered LTG nanoparticles (NPs) using transferrin and lactoferrin as ligand to deliver higher amount of drug to brain and improve the biodistribution and pharmacokinetic profile of drug with prolonged duration of action and reduced accumulation in non-target organs. The LTG NPs were prepared by nanoprecipitation and optimized by factorial design for high entrapment and optimized particle size. The optimized NPs were surface functionalized by conjugating with the lactoferrin (Lf) and transferrin (Tf) as ligands. The developed NPs were characterized for different physicochemical parameters and stability. The in vivo biodistribution showed preferential targeting to brain and reduced accumulation in non-target organs over a prolonged duration of time. Finally, partial sciatic nerve injury model was used to demonstrate the increased pharmacodynamic response as antinociceptive effect. Both biodistribution and pharmacodynamic study in mice confirmed that the approach used for LTG can help to increase clinical applications of LTG due to brain targeting and reduced side effects.

Definitions and mechanisms of drug hypersensitivity

Adverse drug reactions are a difficult problem faced by clinicians in everyday practice. The mechanisms of drug hypersensitivity are not well understood. This is reflected by difficulties in their classification, which is mainly based upon the current knowledge of immunologic and nonimmunologic mechanisms, onset of symptoms (immediate or nonimmediate) and morphology. For the individual patient, the correct diagnosis and classification is important because strict avoidance of the offending drug might be of vital importance. Considerable experience is required to guide management, to interpret results of investigations and to undertake drug challenges. This article summarizes the current knowledge regarding definitions and mechanisms. However, the field of drug hypersensitivity is rapidly expanding. Modern drugs such as biological agents bare hypersensitivity risks that are potentially mediated by, so far, unknown mechanisms.

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.

Stevens–Johnson Syndrome and Toxic Epidermal Necrolysis: Assessment of Medication Risks with Emphasis on Recently Marketed Drugs. The EuroSCAR-Study

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare but severe cutaneous adverse reactions (SCAR) related to a variety of medications. They have a significant public health impact because of high mortality and morbidity. A multinational case-control study conducted in Europe between 1997 and 2001 evaluated the risk of medications to induce SCAR. Cases were actively detected through a hospital network covering more than 100 million inhabitants. Three hospitalized patients per case matched on age, gender, and date of interview were enrolled as controls. After validation by an expert committee blinded to exposures, 379 SCAR cases and 1,505 controls were included. Among drugs recently introduced into the market, strong associations were documented for nevirapine (relative risk (RR)>22) and lamotrigine (RR>14), and weaker associations for sertraline (RR=11 [2.7-46]), pantoprazole (RR=18 [3.9-85]), and tramadol (RR=20 [4.4-93]). Strong associations were confirmed for anti-infective sulfonamides, allopurinol, carbamazapine, phenobarbital, phenytoin, and oxicam-NSAIDs , with some changes in relative numbers of exposed cases. Thus, many cases were still related to a few "old" drugs with a known high risk. Risk was restricted to the first few weeks of drug intake. The use of such drugs as first-line therapies should be considered carefully, especially when safer alternative treatments exist. A number of widely used drugs did not show any risk for SJS and TEN.

Necrolisis epidérmica tóxica por lamotrigina

Toxic epidermal necrolysis (TEN) is a serious entity consisting of a generalized eruption with the formation of flaccid blisters. It affects at least 30 % of the cutaneous surface and is usually related to the prior ingestion of medications. We describe TEN symptoms related to the introduction of lamotrigine, an anti-epileptic drug prescribed in this case for the prevention of migrainous episodes.

Determination of interleukin-5 secretion from drug-specific activated ex vivo peripheral blood mononuclear cells as a test system for the in vitro detection of drug sensitization

BACKGROUND

In vitro detection of drug sensitization is still limited. The lymphocyte transformation test, which determines drug-specific proliferation, is the only in vitro test for detecting drug sensitization at the cellular level irrespective of the reaction's clinical phenotype. Accumulation of eosinophils following IL-5 secretion from drug-specific stimulated T cells is a characteristic histological feature of drug-induced skin eruptions.

OBJECTIVE

We determined whether in vitro drug-specific activation of ex vivo peripheral blood mononuclear cells from 10 patients with drug-induced maculopapular exanthems and three patients with severe skin reactions results in secretion of IL-5, IL-10 or IFN-gamma and assessed the sensitivity and specificity of drug-specific IL-5 secretion as a test system compared with the lymphocyte transformation test and patch tests. Furthermore, the subsets of CD4+ and CD8+ T cells involved in drug-specific proliferation, IL-5 secretion and mRNA expression were examined in three patients.

METHODS

Drug-specific proliferation of peripheral blood mononuclear cells in the lymphocyte transformation test was investigated by 3H-thymidine uptake, and culture supernatants taken after 5 days were analysed for IL-5, IL-10 and IFN-gamma concentrations by ELISA technique. IL-5 mRNA expression was determined by RT-PCR.

RESULTS

Drug-specific activation of peripheral blood mononuclear cells consistently resulted in IL-5 and to a lesser extent in IL-10 and IFN-gamma secretion. The sensitivities of the patch test, lymphocyte transformation test and assessment of drug-specific IL-5 secretion for the detection of drug sensitization were 55%, 75% and 92%, respectively.

CONCLUSION

These data suggest a role for the determination of drug-specific IL-5 secretion by ex vivo peripheral blood mononuclear cells for the in vitro detection of drug-sensitization in drug-induced maculopapular exanthems.

Adverse event monitoring in lamotrigine patients: a pharmacoepidemiologic study in the United Kingdom

PURPOSE

This postmarketing surveillance study of lamotrigine (LTG) was performed to provide complementary data to large-scale Prescription-Event Monitoring study with a retrospective case records survey in five tertiary referral epilepsy centres in the United Kingdom.

METHODS

Adverse events were recorded and compared with those of two other new antiepileptic drugs (AEDs), gabapentin (GBP) and vigabatrin (VGB). All deaths were followed up and standardised mortality ratios (SMRs) were calculated. Serious adverse events were assessed individually.

RESULTS

A total of 2,701 patients was identified as being exposed to LTG and/or the comparators. It was necessary to exclude 1,326 patients because LTG and/or comparators had been commenced outside the study centres. The adverse events with LTG reported by this study were similar to those reported in the literature. Skin rash was the major adverse event. Life-threatening hepatic failure, acute exacerbation of ulcerative colitis, disseminated intravascular coagulation, and renal failure were reported. No death could be directly attributed to the use of LTG. The SMR was slightly higher than that reported in the literature; this probably reflects severity of epilepsy in the study population.

CONCLUSIONS

The safety profile of LTG was similar to that in the large-scale Prescription-Event Monitoring study and generally acceptable. Life-threatening adverse reactions were rare.

Adverse reactions to new anticonvulsant drugs

A lack of systematic pharmacoepidemiological studies investigating adverse drug reactions (ADRs) to anticonvulsants makes it difficult to assess accurately the incidence of anticonvulsant-related ADRs. Most of the available information in this regard stems from clinical trial experience, case reports and postmarketing surveillance, sources that are not, by any means, structured to provide precise data on adverse event epidemiology. For various ethical, statistical and logistical reasons, the organisation of structured clinical trials that are likely to provide substantial data on ADRs is extremely difficult. This review concentrates on current literature concerning serious and life-threatening ADRs. As with the older anticonvulsants, the majority of ADRs to newer anticonvulsants are CNS-related, although there are several that are apparently unique to some of these new drugs. Gabapentin has been reported to cause aggravation of seizures, movement disorders and psychiatric disturbances. Felbamate should only be prescribed under close medical supervision because of aplastic anaemia and hepatotoxicity. Lamotrigine causes hypersensitivity reactions that range from simple morbilliform rashes to multi-organ failure. Psychiatric ADRs and deterioration of seizure control have also been reported with lamotrigine treatment. Oxcarbazepine has a safety profile similar to that of carbamazepine. Hyponatraemia associated with oxcarbazepine is also a problem; however, it is less likely to cause rash than carbamazepine. Nonconvulsive status epilepticus has been reported frequently with tiagabine, although there are insufficient data at present to identify risk factors for this ADR. Topiramate frequently causes cognitive ADRs and, in addition, also appears to cause word-finding difficulties, renal calculi and bodyweight loss. Vigabatrin has been reported to cause seizure aggravation, especially in myoclonic seizures. There have been rare reports of other neurological ADRs to vigabatrin, such as encephalopathy, aphasia and motor disturbances. Vigabatrin-induced visual field constriction is the latest and most worrying ADR. Many questions regarding the nature of this potentially serious ADR remain unanswered, as no prospective controlled study examining the phenomenon has been published. Rare cases of behavioural ADRs and IgA and IgG2 deficiency associated with the use of zonisamide have been reported. However, relatively few patients so far have been exposed to this drug, and therefore more postmarketing information is required. The relatively late establishment of aplastic anaemia and hepatic failure as potentially fatal ADRs of felbamate, and of visual field constriction with vigabatrin, should serve as ample reminders that ADRs can appear at any time.

Factors influencing the incidence of lamotrigine-related skin rash

OBJECTIVE

To determine the incidences of serious and nonserious lamotrigine-related rash, determine the risk factors for lamotrigine-related rash, and evaluate the impact on the incidence of rash of the manufacturer's recommendation to reduce the starting dose of lamotrigine.

METHODS

This was a retrospective case record survey at five tertiary referral epilepsy centers in the UK. The risk factors for lamotrigine-related rash were identified by logistic regression. The independent factors tested were gender, age, epilepsy type, concurrent medication, and starting dose of lamotrigine. The incidences of rash before and after the recommendation of reduction in starting dose were compared by chi2 analysis.

RESULTS

A total of 1050 patients were included. The incidences of serious and nonserious rash were 1.1% (95% CI 0.5% to 1.8%) and 7% (95% CI 5.5% to 8.6%), respectively. Females were at higher risk of developing rash than were males, with a relative risk of 1.8 (95% CI 1.2 to 2.8). The starting dose of lamotrigine was reduced in response to the manufacturer's recommendation, and there was a significant reduction (p = 0.045) in the incidence of serious rash, from 1.5% (12/805) to 0% (0/245). However, there was no reduction in the overall incidence of lamotrigine-related rash, with 63/805 (8%) before and 23/245 (9%) after the recommendation.

CONCLUSIONS

Failure to detect a reduction in the incidence of lamotrigine-related rash since the new (reduced) recommended starting dose of lamotrigine may arise from failure to reduce the starting dose below a critical threshold level, incomplete compliance with current recommendations, or insufficient sample size. The results of this and other studies show that the starting dose of lamotrigine is a significant factor affecting the incidence of rash; furthermore, this study also shows that significant reduction in the incidence of serious rash can be achieved by reducing the starting dose. Therefore, clinicians should not deviate from the recommendations.

Risk of Stevens-Johnson syndrome and toxic epidermal necrolysis during first weeks of antiepileptic therapy: a case-control study. Study Group of the International Case Control Study on Severe Cutaneous Adverse Reactions

BACKGROUND

There is still controversy about whether all antiepileptic drugs are associated with the severe cutaneous reactions Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). We have studied the role of antiepileptic drugs in SJS and TEN, taking into account potential cofactors that might confound or modify the risk.

METHODS

The case-control study in France, Italy, Germany, and Portugal identified cases of SJS/TEN that developed when the patient was not in hospital and were validated by an expert committee. Controls were patients admitted to the same hospital as the case for an acute illness or an elective procedure.

FINDINGS

73 (21%) of the 352 SJS/TEN cases and 28 (2%) of the 1579 controls reported intake of antiepileptic drugs. Among the 73 exposed SJS and TEN patients, 36 reported intake of phenobarbital, 14 of phenytoin, 21 of carbamazepine, 13 of valproic acid, and three of lamotrigine. Risk was highest in the first 8 weeks after onset of treatment. For individual antiepileptic drugs the univariate relative risk of SJS/TEN for 8 weeks or less of use was 57 (95% CI 16-360; multivariate risk 59 [12-302]) for phenobarbital; 91 (26-infinity) for phenytoin; 120 (34-infinity) for carbamazepine; 25 (5.6-infinity) for lamotrigine, and 24 (5.9-infinity) for valproic acid. The result for valproic acid was based on four case users, all of whom reported concurrent use of other associate drugs. The univariate relative risk for more than 8 weeks of use was 6.2 (2.4-17.0; multivariate risk 2.1 [0.5-9.3]) for phenobarbital, 1.2 (0-5.4) for phenytoin, 0.4 (0.02-2.1) for carbamazepine, and 7.0 (2.4-21.0; multivariate risk 2.0 [0.3-15.0]) for valproic acid.

INTERPRETATION

SJS and TEN are associated with short-term therapy with phenytoin, phenobarbital, and carbamazepine. The association with valproic acid seems to be confounded by concomitant short-term therapy with other causal drugs. Lamotrigine also has the potential for severe skin reactions. The period of increased risk is largely confined to the first 8 weeks of treatment.

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.

The use of lamotrigine in neuropathic pain

Sodium channel antagonists have been used in the management of neuropathic pain for several years. Recent evidence suggests that lamotrigine, which is active at glutaminergic excitatory synapses, is very effective in producing pain relief. We have successfully used lamotrigine in two patients suffering from neuropathic pain. Our results suggest that this novel channel antagonist can be used to treat neuropathic pain. Double blind placebo control studies are therefore needed to substantiate these findings.

Suspected lamotrigine-induced toxic epidermal necrolysis

OBJECTIVE

To describe a patient who developed toxic epidermal necrolysis (TEN) possibly secondary to lamotrigine use.

CASE SUMMARY

A 74-year-old white man with a history of probable complex partial seizures was admitted to the neurology service for a prolonged postictal state. His antiepileptic regimen was changed while he was in the hospital to include lamotrigine. After 19 days of hospitalization and 14 days of lamotrigine therapy, the patient became febrile. The next day he developed a rash which progressed within 4 days to TEN, diagnosed by skin biopsy. All suspected drugs were discontinued, including lamotrigine. The patient was treated with hydrotherapy in the burn unit. His symptoms improved and he was discharged from the hospital 26 days after the rash developed.

DISCUSSION

During lamotrigine's premarketing clinical trials, the manufacturer reported several cases of Stevens-Johnson syndrome and TEN. There are several published case reports of lamotrigine-induced severe skin reactions. All of these reports included patients being treated with both valproic acid and lamotrigine. Our patient was exposed to phenytoin, carbamazepine, clindamycin, and lamotrigine, but not valproic acid. The patient reported prior use of phenytoin with no skin rash. Carbamazepine was the antiepileptic drug the patient was maintained on prior to his hospital admission, and the symptoms of TEN resolved while he was still receiving carbamazepine. The patient received only two doses of clindamycin, which makes this agent an unlikely cause of TEN.

CONCLUSIONS

Because of the temporal relationship of the onset of the patient's rash and several drugs that are known to cause severe rashes, it is not certain which drug was the definite culprit. However, based on the evidence from the literature, lamotrigine appears to be the causative agent.