A retrospective study on sequential desensitization-rechallenge for antituberculosis drug allergy

Drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms. Part II diagnosis and management

Drug-induced hypersensitivity syndrome, also known as drug reaction with eosinophilia and systemic symptoms, is a severe cutaneous adverse reaction characterized by an exanthem, fever, and hematologic and visceral organ involvement. The differential diagnosis includes other cutaneous adverse reactions, infections, inflammatory and autoimmune diseases, and neoplastic disorders. Three sets of diagnostic criteria have been proposed; however, consensus is lacking. The cornerstone of management is immediate discontinuation of the suspected drug culprit. Systemic corticosteroids remain first-line therapy, but the literature on steroid-sparing agents is expanding. Longitudinal evaluation for sequelae is recommended. Adjunctive tests for risk stratification and drug culprit identification remain under investigation. Part II of this continuing medical education activity begins by exploring the differential diagnosis and diagnosis of drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms and concludes with an evidence-based overview of evaluation and treatment.

DRESS syndrome due to anti-TB drugs: A complex case with successful re-desensitization of group A drugs

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a rare, life-threatening adverse reaction caused by certain medications. Clinical findings usually include rash, fever, lymphadenopathy, and eosinophilia, and in some cases, they may affect major organs. This reaction caused by antituberculosis (TB) medication poses a public health risk due to treatment discontinuation, adherence, or success in cure. We present a 23-year-old female patient who developed DRESS syndrome as a result of group A anti-TB drugs (ATDs), an exceedingly rare occurrence. The patient's medication was successfully retrieved using a re-desensitization protocol.

Spectrum of anti tubercular therapy induced cutaneous adverse drug reactions and its management through rechallenge: A prospective study at a Tertiary Care Centre

INTRODUCTION

The use of multi-drug regimens including 1st and 2nd line anti tubercular drugs in management of tuberculosis (TB) has been associated with undesirable adverse drug reactions including cutaneous one. Re-challenge remains the only option to restart the safe therapy and combat the tuberculous infection simultaneously.

MATERIALS AND METHODOLOGY

This cross-sectional study was conducted via prospective review of outpatients as well as indoor patients who presented with cutaneous adverse drug reactions to ATT between March 2020 and March 2021. Data were analysed regarding demographic profile, site of TB, ATT regimen, pattern of cutaneous lesions, offending drugs, past history of drug allergy, and reinstitution of ATT after re-challenge.

RESULTS

Out of total 56 registered tubercular patients presented with cutaneous adverse drug reaction 30 were females (53.57%). The most common site of TB was pulmonary followed by cervical lymph node TB. The three most common adverse drug reaction detected were maculopapular rash 32 (57.1%) followed by lichenoid drug eruptions in 6 (10.7%) and urticaria in 2 (3.6%). Ethambutol was found to be common offending drug followed by other first line anti-tubercular drugs. 5 patients developed multiple drug hypersensitivity on re-challenging and have to introduce steroids along with ATT.

CONCLUSION

Adverse cutaneous drug reactions to ATT is like a double-edged sword as stopping ATT and starting treatment with systemic steroids can further flare up the infection with increased risk of disseminated and multidrug resistant tuberculosis. Re-challenge was found out to be safest way in identifying culprit drug and hence to restart a safer alternate ATT regimen for better management.

Desensitization for the prevention of drug hypersensitivity reactions

Drug desensitization is the temporary induction of tolerance to a sensitized drug by administering slow increments of the drug, starting from a very small amount to a full therapeutic dose. It can be used as a therapeutic strategy for patients with drug hypersensitivity when no comparable alternatives are available. Desensitization has been recommended for immunoglobulin E (IgE)-mediated immediate hypersensitivity; however, its indications have recently been expanded to include non-IgE-mediated, non-immunological, or delayed T cell-mediated reactions. Currently, the mechanism of desensitization is not fully understood. However, the attenuation of various intracellular signals in target cells is an area of active research, such as high-affinity IgE receptor (FcεRI) internalization, anti-drug IgG4 blocking antibody, altered signaling pathways in mast cells and basophils, and reduced Ca2+ influx. Agents commonly requiring desensitization include antineoplastic agents, antibiotics, antituberculous agents, and aspirin/nonsteroidal antiinflammatory drugs. Various desensitization protocols (rapid or slow, multi-bag or one-bag, with different target doses) have been proposed for each drug. An appropriate protocol should be selected with the appropriate concentration, dosage, dosing interval, and route of administration. In addition, the protocol should be adjusted with consideration of the severity of the initial reaction, the characteristics of the drug itself, as well as the frequency, pattern, and degree of breakthrough reactions.

'Practical management of suspected hypersensitivity reactions to anti-tuberculosis drugs.'

Tuberculosis (TB) is the commonest cause of death by a single infectious agent globally and ranks amongst the top ten causes of global mortality. The incidence of TB is highest in Low-Middle Income countries (LMICs). Prompt institution of, and compliance with, therapy are cornerstones for a favourable outcome in TB and to mitigate the risk of multiple drug resistant (MDR)-TB, which is challenging to treat. There is some evidence that adverse drug reactions (ADRs) and hypersensitivity reactions (HSRs) to anti-TB drugs occur in over 60% and 3-4% of patients respectively. Both ADRs and HSRs represent significant barriers to treatment adherence and are recognised risk factors for MDR-TB. HSRs to anti-TB drugs are usually cutaneous and benign, occur within few weeks after commencement of therapy and are likely to be T-cell mediated. Severe and systemic T-cell mediated HSRs and IgE mediated anaphylaxis to anti-TB drugs are relatively rare, but important to recognise and treat promptly. T-cell mediated HSRs are more frequent amongst patients with co-existing HIV infection. Some patients develop multiple sensitisation to anti-TB drugs. Whilst skin tests, patch tests and in vitro diagnostics have been used in the investigation of HSRs to anti-TB drugs, their predictive value is not established, they are onerous, require specialist input of an allergist and are resource-dependent. This is compounded by the global, unmet demand for allergy specialists, particularly in low income countries (LICs) / LMICs and now the challenging circumstances of the SARS-CoV-2 pandemic. This narrative review provides a critical analysis of the limited published evidence on this topic and proposes a cautious and pragmatic approach to optimise and standardise the management of HSRs to anti-TB drugs. This includes clinical risk stratification and a dual strategy involving sequential re-challenge and rapid drug desensitisation. Furthermore, a concerted international effort is needed to generate real-time data on ADRs, HSRs, safety and clinical outcomes of these interventions.

Understanding Idiosyncratic Toxicity: Lessons Learned from Drug-Induced Liver Injury

Idiosyncratic adverse drug reactions (IADRs) encompass a diverse group of toxicities that can vary by drug and patient. The complex and unpredictable nature of IADRs combined with the fact that they are rare makes them particularly difficult to predict, diagnose, and treat. Common clinical characteristics, the identification of human leukocyte antigen risk alleles, and drug-induced proliferation of lymphocytes isolated from patients support a role for the adaptive immune system in the pathogenesis of IADRs. Significant evidence also suggests a requirement for direct, drug-induced stress, neoantigen formation, and stimulation of an innate response, which can be influenced by properties intrinsic to both the drug and the patient. This Perspective will provide an overview of the clinical profile, mechanisms, and risk factors underlying IADRs as well as new approaches to study these reactions, focusing on idiosyncratic drug-induced liver injury.

Spectrum of cutaneous adverse drug reactions to anti-tubercular drugs and safe therapy after re-challenge - A retrospective study

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Drug hypersensitivity reactions in Asia: regional issues and challenges

There are geographical, regional, and ethnic differences in the phenotypes and endotypes of patients with drug hypersensitivity reactions (DHRs) in different parts of the world. In Asia, aspects of drug hypersensitivity of regional importance include IgE-mediated allergies and T-cell-mediated reactions, including severe cutaneous adverse reactions (SCARs), to beta-lactam antibiotics, antituberculous drugs, nonsteroidal anti-inflammatory drugs (NSAIDs) and radiocontrast agents. Delabeling of low-risk penicillin allergy using direct oral provocation tests without skin tests have been found to be useful where the drug plausibility of the index reaction is low. Genetic risk associations of relevance to Asia include human leucocyte antigen (HLA)-B*1502 with carbamazepine SCAR, and HLA-B*5801 with allopurinol SCAR in some Asian ethnic groups. There remains a lack of safe and accurate diagnostic tests for antituberculous drug allergy, other than relatively high-risk desensitization regimes to first-line antituberculous therapy. NSAID hypersensitivity is common among both adults and children in Asia, with regional differences in phenotype especially among adults. Low dose aspirin desensitization is an important therapeutic modality in individuals with cross-reactive NSAID hypersensitivity and coronary artery disease following percutaneous coronary intervention. Skin testing allows patients with radiocontrast media hypersensitivity to confirm the suspected agent and test for alternatives, especially when contrasted scans are needed for future monitoring of disease relapse or progression, especially cancers.

Drug hypersensitivity in HIV infection

PURPOSE OF REVIEW

Immune-mediated adverse drug reactions (IM-ADRs) are many times more common in HIV-infected patients. Usual offending drugs include antiretroviral and antiinfectives, but the burden of specific drug IM-ADRs is population-specific; changing as new and fixed dose combinations enter the market, and drug-resistance patterns demand. This review considers recent literature on epidemiology, mechanisms, clinical management and prevention of IM-ADRs amongst persons living with HIV/AIDS.

RECENT FINDINGS

Epidemiological studies continue to describe high rates of delayed hypersensitivity to known offenders, as well as similar reactions in preexposure prophylaxis. IM-ADRs to oral and injectable integrase strand transfer inhibitors are reported with expanding use. The clinical spectrum and management of IM-ADRs occurring in HIV-infected populations is similar to uninfected; with exceptions such as a recently described severe delayed efavirenz DILI with high mortality. Furthermore, the context can be unique, such as the lower than expected mortality in a Stevens-Johnson syndrome and toxic epidermal necrolysis (SJS/TEN) cohort from a HIV/TB high burden setting. Programmatic data showing the near complete elimination of Abacavir drug hypersensitivity syndrome following implementation of HLA-B57:01 screening is a stellar example of how prevention is possible with mechanistic insight.

SUMMARY

IM-ADRs remain a challenge in persons living with HIV. The complexities posed by polypharmacy, overlapping drug toxicities, drug interactions, overlap of IM-ADRs with other diseases, limited alternative drugs, and vulnerable patients with advanced immunosuppression with high mortality, necessitate increased use of drug provocation testing, treat-through and desensitization strategies. There is an urgent need for improved diagnostics and predictive biomarkers for prevention, or to guide treat-through, rechallenge and desensitization approaches.

Hypersensitivity to monoclonal antibodies used for cancer and inflammatory or connective tissue diseases

OBJECTIVE

To review the medical literature on hypersensitivity reactions to therapeutic monoclonal antibodies for patients with malignant tumors and chronic inflammatory or connective tissues diseases.

DATA SOURCES

We searched the PubMed database using the terms monoclonal antibody, hypersensitivity, and allergy.

STUDY SELECTIONS

We selected case reports and cohort studies of patients with hypersensitivity reactions to monoclonal antibodies. We included selected review articles to glean expert opinion on issues for which high-quality data are available. We sought specific information on the incidence, clinical description, pathobiology, and treatment of reactions.

RESULTS

Hypersensitivity reactions to therapeutic monoclonal antibodies can be classic type I (mast cell mediated, perhaps IgE dependent) reactions, cytokine release reactions, or type IV cell-mediated reactions. There are limited data on the frequency of such reactions, and because new agents are added to the set at a relatively high rate, it is difficult to determine precisely the incidence of reactions to this class of drugs as a whole. The classification of a specific hypersensitivity reaction depends mainly on the medical history. Skin testing may be available but often is not validated and may be prohibitively expensive. Avoidance of the culpable agent is ideal, but if treatment with the responsible drug is necessary, rapid drug desensitization is an option for type I reactions. Desensitization is less likely to be effective for cytokine release reactions and is contraindicated for type IV reactions.

CONCLUSION

Hypersensitivity reactions to therapeutic monoclonal antibodies are heterogeneous. Management depends on accurate identification and thoughtful consideration of the pathobiologic features of the reaction.

Management of adverse reactions to first-line tuberculosis antibiotics

PURPOSE OF REVIEW

Tuberculosis (TB) is the commonest infectious cause of death globally. Adverse reactions to first-line tuberculosis antibiotics are common and have a major impact on the outcomes of patients as second-line antibiotics are less effective and more toxic. The present review addresses the most recent literature regarding epidemiology, investigating reactions, and reintroducing treatment in patients who have had their treatment interrupted.

RECENT FINDINGS

Studies have demonstrated that up to 60% of patients experience adverse reactions to TB treatment; around a third of these are idiosyncratic and may relate to immune sensitization. There is an increased risk in patients with HIV. For patients with severe cutaneous reactions patch testing has an important role; however, systemic reactions to patch testing are common in patients with HIV. In-vitro testing remains limited to specialist centers but studies have identified drug-specific lymphocyte responses in patients with cutaneous and liver reactions. Desensitization of patients with severe cutaneous reactions have been demonstrated to be possible, albeit at high risk.

SUMMARY

Management of these patients remains suboptimal. Better identification of predisposing factors, such as HLA alleles, are needed to identify patients at risk. Improved in-vitro diagnostics will reduce the need to re-expose the patient to the drug and optimized desensitization regimens will improve patient safety when drugs have to be re-introduced.

Drug desensitization in allergic children

Drug allergy is an increasing problem worldwide, affecting all populations and races, children and adults, and for which diagnosis and treatment are not well standardized yet. Besides classical treatments, new drugs have been developed, especially for patients suffering from malignancies and chronic inflammatory diseases, that specifically target the cause of the disease. For those patients requiring such molecules, it is sometimes difficult to find an alternative drug when hypersensitivity reactions occur. Desensitization is therefore the best option whenever no alternative therapy is available but also when alternative treatments are considered therapeutically inferior and or more toxic. Despite its clinical success, little is known about the mechanisms and molecular targets of drug desensitization. Desensitization protocols use a gradual dose escalation to allow the safe administration of a treatment to which a patient previously presented a hypersensitivity reaction. The procedure requires special training and coordination of an allergy team, including physicians, nurses, and pharmacists, working together to safely and successfully implement desensitization protocols when appropriate. There is no difference in desensitization protocol between adults and children, except for the final cumulative dose of the administered drug.

Efficacy and tolerability of desensitization in the treatment of delayed drug hypersensitivities to anti-tuberculosis medications

BACKGROUND

Delayed drug hypersensitivity to first-line anti-tuberculosis medication is a major challenge in tuberculosis treatment.

OBJECTIVE

This study was performed to investigate the efficacy/tolerability of desensitization therapy in treatment of first-line anti-tuberculosis medication hypersensitivity and the usefulness of immunologic evaluation therein.

METHODS

This study was conducted as a prospective, observational cohort study. Subjects who experienced hypersensitivity reactions, including maculopapular exanthema (MPE) and drug reaction with eosinophilia and systemic symptoms (DRESS), to first-line anti-tuberculosis medications (isoniazid [INH], ethambutol [EMB], rifampin [RFP], and pyrazinamide [PZA]) were enrolled. Patch, intradermal, lymphocyte transformation, and oral provocation tests were performed to determine culprit drugs, which were desensitized with rapid and graded challenge protocols. Breakthrough reactions (BTRs) during or after desensitization were assessed.

RESULTS

In total, 31 desensitization treatments (INH, 8; EMB, 8; RFP, 11; PZA, 4) to 12 patients (8 with MPE and 4 with DRESS) were performed. The overall success rate of desensitization was 80.7%. All the study subjects except one completed the full course of anti-tuberculosis treatment. The overall BTR free rate was 64.5%. Sixteen (80%) treatments for MPE and four (36.4%) for DRESS were BTR free (P = 0.023). Drugs that were positive on any two of three immunologic studies showed significantly high BTR rates (P = 0.014), although this was not correlated with desensitization failure rate.

CONCLUSION

Rapid desensitization therapy to multiple anti-tuberculosis medications for delayed drug hypersensitivity was safe and successful. Combination of multiple immunologic evaluations may predict BTR although it needs validation in larger studies.

Successful rapid oral desensitization for dual hypersensitivity to isoniazid and rifampin while treating central nervous system tuberculosis

Tuberculosis of the central nervous system (CNS-TB) is a critical disease with poor prognosis if not diagnosed and treated early. A regimen of drugs with good CNS penetration is required for treatment. Treatment options are limited in case of hypersensitivity reaction of the recommended regimen. We are reporting a rare instance where a patient developed hypersensitivity to both first line agents (isoniazid and rifampin) for CNS-TB and was successfully desensitized against both these medications to complete the treatment course using the rapid desensitization process. There have been reported cases of desensitization to anti tuberculous medications in cases with pulmonary tuberculosis and hypersensitivity reaction. In this review article we discuss the prior used methods of slow and rapid desensitization in case on non-CNS tuberculosis infections. This is the first reported case to use similar method of rapid desensitization in treatment of central nervous system infection.

Tolerance Induction to Antituberculosis Drugs in a Patient With Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis Overlap

Tolerance induction and desensitization in Stevens-Johnson syndrome (SJS) or in toxic epidermal necrolysis (TEN) have been described as an absolute contraindication by some authors, but there are cases where there is no treatment alternative. Tuberculosis (TB) remains a leading cause of morbidity and mortality in developing countries and ranks alongside HIV as a leading cause of death worldwide. Severe drug reactions, such as SJS and TEN, occurring in these individuals are lifethreatening. Since alternative therapies for TB are limited, the role of desensitization and reintroduction becomes essential. We describe a case of tolerance induction to anti-TB drugs in a patient with SJS/TEN overlap syndrome using a specifically designed premedication, comedication, and desensitization protocol.

Successful drug desensitization in patients with delayed-type allergic reactions to anti-tuberculosis drugs

OBJECTIVE

To evaluate the outcomes of anti-tuberculosis drug desensitization.

METHODS

This was a retrospective study. Inclusion criteria were as follows: age >18years, documented tuberculosis infection, a previous cutaneous allergic reaction to anti-tuberculosis drugs, and having undergone drug desensitization between January 2003 and March 2014. The definition of allergic reaction to anti-tuberculosis drugs included (1) a temporal relationship between drug use and the allergic reaction; (2) improvement in the allergic reaction after drug withdrawal; (3) recurrence of the allergic reaction after reintroduction of only the offending drug; and (4) absence of other causes.

RESULTS

A total of 19 desensitization procedures were performed. The drugs used for these procedures were isoniazid (n=7), rifampicin (n=6), or ethambutol (n=6). Of note, severe allergic reactions (Stevens-Johnson syndrome (n=4), erythema multiforme (n=3), and drug rash with eosinophilia and systemic syndrome (n=1)) were included. All patients underwent resolution of the previous allergic reactions before desensitization. The median duration of desensitization was 18 days. The success rate was 78.9%. The allergic reactions following failed desensitization were not severe; most were maculopapular rashes.

CONCLUSIONS

The desensitization protocol for anti-tuberculosis drugs was associated with a high success rate, and the individuals who failed desensitization experienced mild allergic reactions.

Antituberculosis Drug-Associated DRESS: A Case Series

BACKGROUND

Although antituberculosis drug-associated drug reaction with eosinophilia and systemic symptoms (DRESS) is rarely reported, its diagnosis should not be dismissed. Its management implies an early withdrawal of suspected drugs.

OBJECTIVE

The objective of this study was to describe the characteristics of antituberculosis drug-associated DRESS and to identify the most likely involved drugs.

METHODS

We searched for potential cases of DRESS with rifampicin, isoniazid, pyrazinamide, and ethambutol reported from January 1, 2005, to July 30, 2015, in the French pharmacovigilance database. A literature review was also performed.

RESULTS

Sixty-seven cases of antituberculosis drug-associated DRESS were analyzed (40 women and 27 men, median age of 61 years). Liver and kidneys were the most frequently involved organs. Two patients died from DRESS. Skin tests were performed in 11 patients and were positive in 8 cases. Discrepancies between epicutaneous tests and reintroduction of the culprit drugs were observed for 2 patients with a premature reintroduction of antituberculosis drugs in 1 case. Antituberculosis drugs were the only suspects in 20 cases. As for the literature data, rifampicin was the most suspected drug because of its larger indications, but in case of tuberculosis infections, isoniazid was the most suspected drug.

CONCLUSIONS

We described the largest case series of first-line antituberculosis drug-associated DRESS in the literature. All antituberculosis drugs pose a risk of DRESS. An early withdrawal of the culprit drugs is essential. A drug allergy evaluation must be performed to optimize the second-line treatment of tuberculosis infection.

"Treating Through" Decision and Follow-up in Antibiotic Therapy-Associated Exanthemas

BACKGROUND

Immediate discontinuation or replacement of suspected drugs is considered standard medical care in acute exanthematous skin reactions. In the treatment of bacterial infections, structurally different alternative antibiotics, however, are commonly second choice options due to a suboptimal antimicrobial activity or an unfavorable side effect profile. Nonetheless, "treating through," the continuation of antibiotic treatment despite an objective exanthema, is practiced only rarely.

OBJECTIVE

We aimed to assess whether "treating through" is an option for patients with severe bacterial soft tissue infections (severe cellulitis) who experience maculopapular exanthema (MPE) during antibiotic therapy.

METHODS

We retrospectively reviewed clinical data from 18 patients who developed MPE within a few days after initiation of intravenous antibiotic treatment. A decision to "treat through" was made when the suspected antibiotics (β-lactams, clindamycin, ciprofloxacin) were clinically effective and the benefits of continued treatment outweighed potential risks. Clinical and laboratory findings were closely monitored in an inpatient setting.

RESULTS

In 2 patients, a modification of antibiotic therapy was deemed necessary due to a significant increase of liver enzymes within 4 days after the initial decision to "treat through." Because of a progression of MPE under ongoing treatment with cefuroxime and clindamycin, clindamycin was discontinued in 1 patient. In another 3 patients, antibiotic treatment was modified because of insufficient improvement of the soft tissue infection. In the remaining 12 "treated through" cases, the skin symptoms improved despite unchanged continued antibiotic treatment, and relevant laboratory parameters remained within the normal range.

CONCLUSIONS

Careful risk-benefit assessment may enable the continuation of antibiotic therapy despite MPE, provided that patients are under close medical observation.

Drug-induced liver injury: Do we know everything?

Interest in drug-induced liver injury (DILI) has dramatically increased over the past decade, and it has become a hot topic for clinicians, academics, pharmaceutical companies and regulatory bodies. By investigating the current state of the art, the latest scientific findings, controversies, and guidelines, this review will attempt to answer the question: Do we know everything? Since the first descriptions of hepatotoxicity over 70 years ago, more than 1000 drugs have been identified to date, however, much of our knowledge of diagnostic and pathophysiologic principles remains unchanged. Clinically ranging from asymptomatic transaminitis and acute or chronic hepatitis, to acute liver failure, DILI remains a leading causes of emergent liver transplant. The consumption of unregulated herbal and dietary supplements has introduced new challenges in epidemiological assessment and clinician management. As such, numerous registries have been created, including the United States Drug-Induced Liver Injury Network, to further our understanding of all aspects of DILI. The launch of LiverTox and other online hepatotoxicity resources has increased our awareness of DILI. In 2013, the first guidelines for the diagnosis and management of DILI, were offered by the Practice Parameters Committee of the American College of Gastroenterology, and along with the identification of risk factors and predictors of injury, novel mechanisms of injury, refined causality assessment tools, and targeted treatment options have come to define the current state of the art, however, gaps in our knowledge still undoubtedly remain.

Alectinib-Induced Erythema Multiforme and Successful Rechallenge with Alectinib in a Patient with Anaplastic Lymphoma Kinase-Rearranged Lung Cancer

Background

Alectinib is an oral drug developed for the treatment of patients with fusion gene encoding echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK)-rearranged non-small cell lung cancer (NSCLC). Here, we present the case of a patient treated with alectinib who developed a hypersensitivity reaction with successful rechallenge treatment.

Case Presentation

A 39-year-old woman who was a passive smoker was referred to Osaka City University Hospital for the evaluation of a skin event caused by treatment for NSCLC with the fusion gene EML4-ALK. The skin reaction was observed on the anterior chest, upper arms, and ear auricles on day 11 of treatment with oral alectinib. The skin event presented as widely distributed erythematous macules that were confluent, indicating a severe and life-threatening form. The skin lesions started to resolve after the initiation of treatment with 40 mg prednisolone. After regrowth of the tumor, she received a rechallenge program for alectinib for 2 weeks; thereafter, alectinib treatment was successfully reinitiated.

Conclusion

To the best of our knowledge, we present the first case in which alectinib, which binds to the adenosine triphosphate site of EML4-ALK, induced erythema multiforme. Moreover, successful readministration of alectinib through our rechallenge program has not been reported so far.

The Art and Science of Diagnosing and Managing Drug-induced Liver Injury in 2015 and Beyond

Drug-induced liver injury (DILI) remains a leading reason why new compounds are dropped from further study or are the subject of product warnings and regulatory actions. Hy's Law of drug-induced hepatocellular jaundice causing a case-fatality rate or need for transplant of 10% or higher has been validated in several large national registries, including the ongoing, prospective U.S. Drug-Induced Liver Injury Network. It serves as the basis for stopping rules in clinical trials and in clinical practice. Because DILI can mimic all known causes of acute and chronic liver disease, establishing causality can be difficult. Histopathologic findings are often nonspecific and rarely, if ever, considered pathognomonic. A daily drug dose >50-100 mg is more likely to be hepatotoxic than does <10 mg, especially if the compound is highly lipophilic or undergoes extensive hepatic metabolism. The quest for a predictive biomarker to replace alanine aminotransferase is ongoing. Markers of necrosis and apoptosis such as microRNA-122 and keratin 18 may prove useful in identifying patients at risk for severe injury when they initially present with a suspected acetaminophen overdose. Although a number of drugs causing idiosyncratic DILI have HLA associations that may allow for pre-prescription testing to prevent hepatotoxicity, the cost and relatively low frequency of injury among affected patients limit the current usefulness of such genome-wide association studies. Alanine aminotransferase monitoring is often recommended but has rarely been shown to be an effective method to prevent serious DILI. Guidelines on the diagnosis and management of DILI have recently been published, although specific therapies remain limited. The LiverTox Web site has been introduced as an interactive online virtual textbook that makes the latest information on more than 650 agents available to clinicians, regulators, and drug developers alike.