A case report of olanzapine-induced hypersensitivity syndrome

Is Vitamin B12 Level a Reliable Predictor of Psychosis Severity in Male Patients with Megaloblastic Anemia at a Single Tertiary Hospital?

Background

Megaloblastic anemia (MA) occurs due to ineffective erythropoiesis, which results from impaired DNA synthesis in the hematopoietic precursors and intramedullary hemolysis. MA’s most common cause is nutritional deficiencies of either cobalamin (vitamin B12) or folate (vitamin B6). This study aims to determine the association between MA caused by vitamin B12 deficiency and psychosis among psychotic male patients in Mental Health Hospital at Taif, Saudi Arabia.

Methods

Fifty psychotic male patients, aged 48.58±1.72, were recruited from the Mental Health Hospital at Taif, Saudi Arabia, in addition to 54 sex-matched healthy controls. The following tests were run: complete blood count (CBC), liver function tests (LFT), serum levels of vitamin B12, folate, and C-reactive protein (CRP).

Results

The CBC showed that RBCs count, haemoglobin, haematocrit, platelets count, mean platelets volume (MPV), and absolute lymphocyte count were significantly lower in psychotic patients versus healthy controls (P=0.007, P=0.002, P=0.001, P=0.004, P=0.0001, and P=0.005, respectively). In contrast, the eosinophil absolute count and basophil percentage were significantly higher in psychotic patients versus controls (P=0.009, P=0.0001, respectively). Vitamin B12 levels were insignificantly decreased in psychotic patients versus healthy group. There were significant negative correlations between serum levels of VitB12 and negative symptoms (r=−0.381, P=0.006) and hallucination (r=−0.297, P=0.036).

Conclusion

These findings indicate no link between MA induced by VitB12 insufficiency and psychosis among psychotic patients. However, low serum VitB12 can predict the severity of some psychosis signs, including hallucinations and negative symptoms. Therefore, monitoring VitB12 levels and its supplementation in psychotic patients is recommended to improve their symptoms.

Olanzapine-Induced Elevated Liver Function Tests in an Older Person Treated for Antidepressant-Induced Mania

Patient History A 67-year-old male presented with symptoms of mania eight days after switching from sertraline to bupropion. His past medical history included benign prostatic hyperplasia, erectile dysfunction, insomnia, and a recent diagnosis of depression. He denied previous history of depression but reported taking sertraline for premature ejaculation, an off-label use. His baseline aspartate aminotransferase (AST) was 20 U/L and alanine transaminase (ALT) was 22 U/L. Bupropion was held on admission and olanzapine 5 mg nightly was initiated to treat mania. Following six days of olanzapine treatment, his liver function tests (LFTs) were elevated (AST = 83 U/L, ALT = 105 U/L) and peaked two days later at AST being 2,024 U/L and ALT being 1,508 U/L. Other causes of LFT elevation were ruled out since no other new medications were started and the patient denied use of acetaminophen. Olanzapine was subsequently discontinued and his LFTs began to improve. His symptoms of mania resolved, and he was discharged on no psychotropic medications. Review of Literature A literature search identified 6 cases of bupropion-induced mania/hypomania and 10 cases of olanzapine-induced increased LFTs. This case will add to the limited reports regarding these adverse effects. Conclusion Possible adverse drug reactions (ADRs) were observed between the initiation of bupropion and the development of manic symptoms as well as the initiation of olanzapine and elevated LFTs. The case report also focuses on the role of pharmacy in a patient with multiple ADRs from psychotropic medications and the importance of gaining collateral information and clarifying indications of prescribed medications.

Bipolar Patients and Bullous Pemphigoid after Risperidone Long-Acting Injectable: A Case Report and a Review of the Literature

Neuropsychiatric disorders are found to be associated with bullous pemphigoid (BP), an autoimmune subepidermal blistering disease. Antipsychotics have emerged as possible inducing factors of BP. However, large sample studies concerning BP associated with antipsychotics, as well as with specific mental disorders, are still lacking. Our review retrieved a few clinical studies and case reports on the topic, producing controversial results. We report for the first time a bipolar patient case presenting BP following five-month therapy with risperidone long-acting injectable (LAI). We hypothesize that the dermatological event is associated with the medication administered. The issue emerged during psychiatric consultation and was confirmed by histological examination, direct and indirect immunofluorescence studies, plus positive plasma and cutaneous BP180 and BP230 IgG. Neurodegeneration or neuroinflammation might represent a primary process leading to a cross-reactive immune response between neural and cutaneous antigens and contributing to self-tolerance failure. Furthermore, the time sequence of the shared biological mechanisms leading to clinical manifestations of the neuropsychiatric disorder and BP remains undefined. BP comorbid with bipolar disorder might occasionally represent a serious health risk and affect patients' physical and psychosocial quality of life. Thus, clinicians treating psychiatric patients should consider BP as a possible adverse effect of psychotropic medications.

Association of antipsychotic use with raised eosinophil count

The current study aimed to assess the possibility of an association between first and second generation antipsychotic medication and raised eosinophil count. A total of 22 in-patients at the psychiatric unit of the University General Hospital ‘Attikon’, a tertiary hospital, were included in the present study. Patients had received antipsychotic monotherapy and did not have any co-morbidities or require additional treatments. Patients were monitored weekly and their eosinophil count was assessed. One-way ANOVA and summary measures analysis were applied to study the effect of time and medication type on the absolute eosinophil concentration (or relative percentage) for each patient. The differences in mean eosinophil concentrations or relative percentage by patient and time were also assessed. An increase in the absolute concentration and the relative percentage of eosinophils over time was observed in patients receiving Olanzapine, Haloperidol and Aripiprazole. However, there was no difference between individual medications. In conclusion, antipsychotics may be associated with increased eosinophil count over time; however, larger studies involving more patients and a longer follow-up are required to reach a definitive conclusion.

Immunoendocrine Peripheral Effects Induced by Atypical Antipsychotics

Atypical antipsychotics (AAP) or second-generation antipsychotics are the clinical option for schizophrenia treatment during acute psychoses, but they are also indicated for maintenance during lifetime, even though they are being used for other psychiatric conditions in clinical practice such as affective disorders and autism spectrum disorder, among others. These drugs are differentiated from typical antipsychotics based on their clinical profile and are a better choice because they cause fewer side effects regarding extrapyramidal symptoms (EPS). Even though they provide clear therapeutic benefits, AAP induce peripheral effects that trigger phenotypic, functional, and systemic changes outside the Central Nervous System (CNS). Metabolic disease is frequently associated with AAP and significantly impacts the patient's quality of life. However, other peripheral changes of clinical relevance are present during AAP treatment, such as alterations in the immune and endocrine systems as well as the intestinal microbiome. These less studied alterations also have a significant impact in the patient's health status. This manuscript aims to revise the peripheral immunological, endocrine, and intestinal microbiome changes induced by AAP consumption recommended in the clinical guidelines for schizophrenia and other psychiatric disorders.

Hepatic Safety of Atypical Antipsychotics: Current Evidence and Future Directions

The newer atypical antipsychotic agents (AAPs) represent an attractive therapeutic option for a wide range of psychotic disorders, including schizophrenia and bipolar mania, because of the reduced risk of disabling extrapyramidal symptoms. However, their growing use has raised questions about their tolerability over the endocrine, metabolic, and cardiovascular axes. Indeed, atypical antipsychotic drugs are associated, to differing extents, with mild elevation of aminotransferases related to weight gain, AAP-induced metabolic syndrome, and nonalcoholic fatty liver disease. Although the hepatic safety of new AAPs seems improved over that of chlorpromazine, they can occasionally cause idiosyncratic liver injury with varying phenotypes and, rarely, lead to acute liver failure. However, AAPs are a group of heterogeneous, chemically unrelated compounds with distinct pharmacological and pharmacokinetic properties and substantially different safety profiles, which precludes the notion of a class effect for hepatotoxicity risk and highlights the need for an individualized therapeutic approach. We discuss the current evidence on the hepatotoxicity potential of AAPs, the emerging underlying mechanisms, and the limitations inherent to this group of drugs for both establishing a proper causality assessment and developing strategies for risk management.

DRESS syndrome: Addressing the drug hypersensitivity syndrome on combination of Sodium Valproate and Olanzapine

A case of an adolescent with symptoms of Mania, who developed Drug Reaction with Eosinophilia and Systemic Symptom (DRESS) syndrome on exposure to combination of oral Olanzapine and Sodium Valproate is presented. We have attempted to highlight the atypical presentation of DRESS syndrome in this patient as well as management difficulties in patient who develops DRESS syndrome with the conventional psychotropic medication. Hence, it is necessary for mental health professionals to be vigilant about this life threatening drug reaction associated with high morbidity and mortality, thus ensuring prompt diagnosis and management.

Olanzapine-induced Skin Eruptions

Adverse cutaneous reactions are known to occur with psychotropic medications, which may lead to poor drug compliance. As compared to other group of psychotropics, there is relatively scarce literature on olanzapine-induced skin eruptions. We present a case of a 39-year-old man diagnosed with first episode mania and alcohol dependence syndrome who was started on tablet olanzapine which leads to fixed drug eruptions. Exhaustive investigations were done, all of which came out within normal limits. A diagnosis of fixed drug eruptions was made by the dermatologist. The skin eruptions subsided after stopping olanzapine. It has, thus, been emphasized that clinicians should be aware of the potential cutaneous eruptions associated with olanzapine. Early detection of the same would lead to timely management and hence better compliance with the psychotropic treatment.

Management of Hepatotoxicity Induced by the Use of Olanzapine

Numerous drugs cause hepatotoxicity clinically or biologically. Neuropsychiatric drugs constitute 16% of these drugs. The occurrence of hepatotoxicity induced by the use of olanzapine is expressed by the researchers. In such cases, generally the dose of olanzapine is reduced or the drug is completely discontinued and the treatment of the patient fails. The aim of this study is to report the case for whom elevated liver enzymes were observed but the process was managed without changing treatment dose and drug and to discuss this case with literature information. The present study has characteristics of being the first in the literature concerning management of the process.

Psychotropic drugs and liver disease: A critical review of pharmacokinetics and liver toxicity

The liver is the organ by which the majority of substances are metabolized, including psychotropic drugs. There are several pharmacokinetic changes in end-stage liver disease that can interfere with the metabolization of psychotropic drugs. This fact is particularly true in drugs with extensive first-pass metabolism, highly protein bound drugs and drugs depending on phase I hepatic metabolic reactions. Psychopharmacological agents are also associated with a risk of hepatotoxicity. The evidence is insufficient for definite conclusions regarding the prevalence and severity of psychiatric drug-induced liver injury. High-risk psychotropics are not advised when there is pre-existing liver disease, and after starting a psychotropic agent in a patient with hepatic impairment, frequent liver function/lesion monitoring is advised. The authors carefully review the pharmacokinetic disturbances induced by end-stage liver disease and the potential of psychopharmacological agents for liver toxicity.

Case report of eosinophilia induced by quetiapine

An increase in the concentration of eosinophils in blood may lead to endocarditis, myocarditis, and pericarditis. When the absolute eosinophil count increases beyond 1.5 x 10⁹/L, myocardial damage and even death can occur. This case report describes a 47-year-old male with an alcohol-induced psychotic disorder who developed eosinophilia 4 weeks after starting treatment with quetiapine 50-200 mg/d. His maximum recorded absolute eosinophil count was 7.63 x 10⁹/L (normal range < 0.5 x 10⁹/L), but the level returned to normal over a 4-week period after stopping quetiapine and no myocardial damage was observed. This patient’s dramatic eosinophilia did not have any associated clinical symptoms; it was only identified as part of a routine blood test a few weeks after starting quetiapine. This is a reminder that all clinicians who treat patients with antipsychotic medications must be vigilant about the occurrence of such rare but life-threatening adverse events.

Drug-Induced Liver Injury during Antidepressant Treatment: Results of AMSP, a Drug Surveillance Program

BACKGROUND

Drug-induced liver injury is a common cause of liver damage and the most frequent reason for withdrawal of a drug in the United States. The symptoms of drug-induced liver damage are extremely diverse, with some patients remaining asymptomatic.

METHODS

This observational study is based on data of Arzneimittelsicherheit in der Psychiatrie, a multicenter drug surveillance program in German-speaking countries (Austria, Germany, and Switzerland) recording severe drug reactions in psychiatric inpatients. Of 184234 psychiatric inpatients treated with antidepressants between 1993 and 2011 in 80 psychiatric hospitals, 149 cases of drug-induced liver injury (0.08%) were reported.

RESULTS

The study revealed that incidence rates of drug-induced liver injury were highest during treatment with mianserine (0.36%), agomelatine (0.33%), and clomipramine (0.23%). The lowest probability of drug-induced liver injury occurred during treatment with selective serotonin reuptake inhibitors ([0.03%), especially escitalopram [0.01%], citalopram [0.02%], and fluoxetine [0.02%]). The most common clinical symptoms were nausea, fatigue, loss of appetite, and abdominal pain. In contrast to previous findings, the dosage at the timepoint when DILI occurred was higher in 7 of 9 substances than the median overall dosage. Regarding liver enzymes, duloxetine and clomipramine were associated with increased glutamat-pyruvat-transaminase and glutamat-oxalat-transaminase values, while mirtazapine hardly increased enzyme values. By contrast, duloxetine performed best in terms of gamma-glutamyl-transferase values, and trimipramine, clomipramine, and venlafaxine performed worst.

CONCLUSIONS

Our findings suggest that selective serotonin reuptake inhibitors are less likely than the other antidepressants, examined in this study, to precipitate drug-induced liver injury, especially in patients with preknown liver dysfunction.

Involvement of oxidative stress and mitochondrial/lysosomal cross-talk in olanzapine cytotoxicity in freshly isolated rat hepatocytes

1. Olanzapine (OLZ) is a widely used atypical antipsychotic agent for the treatment of schizophrenia and other disorders. Serious hepatotoxicity and elevated liver enzymes have been reported in patients receiving OLZ. However, the cellular and molecular mechanisms of the OLZ hepatotoxicity are unknown. 2. In this study, the cytotoxic effect of OLZ on freshly isolated rat hepatocytes was assessed. Our results showed that the cytotoxicity of OLZ in hepatocytes is mediated by overproduction of reactive oxygen species (ROS), mitochondrial potential collapse, lysosomal membrane leakiness, GSH depletion and lipid peroxidation preceding cell lysis. All the aforementioned OLZ-induced cellular events were significantly (p < 0.05) prevented by ROS scavengers, antioxidants, endocytosis inhibitors and adenosine triphosphate generators. Also, the present results demonstrated that CYP450 is involved in OLZ-induced oxidative stress and cytotoxicity mechanism. 3. It is concluded that OLZ hepatotoxicity is associated with both mitochondrial/lysosomal involvement following the initiation of oxidative stress in hepatocytes.

Quetiapine-induced myocarditis presenting as acute STEMI

An 18-year-old man diagnosed with attention-deficit hyperactivity disorder was recently started on quetiapine in addition to regular methylphenidate, which he had been taking for a number of years. He presented with chest pain and inferolateral ST elevation, and underwent urgent coronary angiography, which showed normal coronary arteries. The initial troponin level was raised and an inpatient echocardiogram showed mild left ventricular systolic dysfunction with no evidence of regional wall motion abnormality. Cardiac MRI showed subepicardial late gadolinium enhancement, which was suggestive of myocarditis. Quetiapine and methylphenidate were discontinued and the patient was discharged home after 1 week. He was followed up within 8 weeks with complete recovery and no symptoms.

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.

Olanzapine-induced eccrine squamous syringometaplasia

Eccrine squamous syringometaplasia is a histopathologic pattern that has mainly been described in patients receiving chemotherapy. Its association to nonchemotherapeutic agents is rare, with very few cases reported in the literature. We present the case of a 55-year-old patient with schizophrenia, who developed a skin eruption 5 weeks after initiating treatment with olanzapine. The histopathologic study revealed squamous syringometaplasia of the dermal eccrine ducts.

The DRESS syndrome: a literature review

The Drug Reaction with Eosinophilia and Systemic Symptom (DRESS) is a severe adverse drug-induced reaction. Diagnosing DRESS is challenging due to the diversity of cutaneous eruption and organs involved. We used the RegiSCAR scoring system that grades DRESS cases as "no," "possible," "probable," or "definite" to classify cases reported in the literature. We also analyzed the clinical course and treatments of the cases. A total of 44 drugs were associated with the 172 cases reported between January 1997 and May 2009 in PubMed and MEDLINE. The most frequently reported drug was carbamazepine, and the vast majority of cases were classified as "probable/definite" DRESS cases. Hypereosinophilia, liver involvement, fever, and lymphadenopathy were significantly associated with "probable/definite" DRESS cases, whereas skin rash was described in almost all of the cases, including "possible cases." Culprit drug withdrawal and corticosteroids constituted the mainstay of DRESS treatment. The outcome was death in 9 cases. However, no predictive factors for serious cases were found. This better knowledge of DRESS may contribute to improve the diagnosis and management of this syndrome in clinical practice.

A review of liver function tests during treatment with atypical antipsychotic drugs: a chart review study

OBJECTIVE

Atypical antipsychotic drugs commonly cause asymptomatic increase in the liver enzymes and serum bilirubin levels. However they rarely may induce a serious hepatic toxicity. In this article we aimed to evaluate the effect of atypical antipsychotic drugs namely olanzapine, risperidone and quetiapine on the hepatic enzymes and serum bilirubin levels in psychiatric patients.

METHOD

Chart reviews of 312 patient followed-up at Psychiatry Department of Zonguldak Karaelmas University Hospital were examined in detail. The patients whose baseline and follow-up liver function tests including alanine aminotransfeaminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), alkaline phosphotase (ALP) and serum bilirubin that were measured before and within the treatment period of first and sixth months were enrolled. Forty eight males and 62 females whose ages ranging from 12 to 65 years were eligible for this study (no pregnant case was present).

RESULTS

The repartition according to treatment is as follows: olanzapine (n=33), risperidone (n=29), and quetiapine (n=48). Two of the 110 patients (1.8%) presented with increased AST levels of up to 4 fold and ALT of thrice the basal level and needed to stop treatment (AST increase in one female with olanzapine 20 mg/day; ALT increase in one male with olanzapine 30 mg/day). Thirty of the 110 patients (27.2%) showed asymptomatic increases in ALT, AST, GGT and serum bilirubin levels in the first month of the study. After 6 months of the treatment, abnormalities in the liver function tests were observed in 25 patients (22.7%).

CONCLUSION

These results were in accordance with previous studies that asymptomatic increase of liver enzymes are common but significant liver enzyme elevations are rare during atypical antipsychotic treatment. We suggest that obtaining baseline liver enzyme tests before atypical antipsychotic therapy and monitoring regularly specifically in patients with risk factors for liver damage during therapy.

Severe liver enzyme elevations after three years of olanzapine treatment: a case report and review of olanzapine associated hepatotoxicity

Atypical antipsychotics commonly cause isolated asymptomatic increase in the aminotransferase levels. Among these atypical antipsychotics, mostly transient, asymptomatic increase in hepatic enzymes has been reported with olanzapine, however olanzapine rarely may induce a clinical and/or biological hepatic toxicity. The pathogenesis of olanzapine-associated hepatotoxicity is not well known and is mostly a transient phenomenon. However, substantial and lasting changes may occur and result in symptomatic hepatitis. In the following case report, we report on a 44-year-old female patient diagnosed as Bipolar Disorder Type I, whose liver enzyme levels increased ten fold of normal ranges during the third year of the olanzapine treatment and returned to the normal levels within three weeks after olanzapine discontinuation. Although significant liver enzyme elevations are uncommon during olanzapine treatment, based on reports of serious hepatotoxicity, controlled and longitudinal research are needed to learn side effects of this drug on liver. Clinicians should be aware of possible hepatotoxic effects of atypical antipsychotics and should monitor the liver enzyme levels whenever they feel necessary.

Life-threatening acute adverse cutaneous drug reactions

Adverse cutaneous reactions to drugs are frequent, affecting 2% to 3% of all hospitalized patients. Fortunately, only about 2% of adverse cutaneous reactions are severe and very few are fatal. Stevens-Johnson syndrome and toxic epidermal necrolysis are severe life-threatening diseases with a mortality rate reaching 30%, and only prompt recognition and diagnosis, withdrawal of the offensive drug, and referral to an intensive care unit or burn care unit might improve the prognosis and save the patient's life. Drug eruption with eosinophilia and systemic symptoms syndrome, formerly termed drug hypersensitivity syndrome, is a rather distinct severe adverse drug reaction (ADR) characterized by eruption, fever, lymph node enlargement, and single or multiple organ involvement, with a high morbidity and a mortality rate of 10%. These severe ADRs, together with serum sickness-like syndrome, are discussed in this review. Other severe reactions, such as anaphylaxis and vasculitis, are discussed elsewhere in this issue. Although most of the readers, particularly those in the outpatient arena, will not be treating these patients, they are the ones who will see them first, diagnose them, realize the potential danger in their condition, and refer them to the appropriate treatment venue. Therefore, dermatologists should be familiar with these conditions and be prepared to handle them adequately.

Guillain-Barré-like Syndrome Associated With Olanzapine Hypersensitivity Reaction

Olanzapine is the most commonly prescribed atypical antipsychotic drug. Recently there has been increased concern over possible adverse metabolic effects of this drug. The authors describe the first case of Guillain-Barré-like syndrome associated with an olanzapine hypersensitivity reaction. The presence of progressive numbness, motor weakness, or pain in the limbs of patients receiving olanzapine should raise suspicion of Guillain-Barré syndrome.

Hepatotoxicity, leucopenia and neutropenia associated with olanzapine therapy

Hepatotoxicity, leukopenia and neutropenia are rarely associated with atypical antipsychotic drug therapy. The authors describe a case of a schizophrenic patient, who was treated twice with olanzapine, and who developed an increase of hepatic enzymes, jaundice, reduced WBC, neutropenia, and a high temperature. The patient was diagnosed as suffering from hepatocellular hepatitis, neutropenia and leucopenia. Neuroleptic treatment was discontinued immediately and the patient exhibited consequential clinical improvement. A review of the literature is included.

Adverse cutaneous reactions to antipsychotics

Antipsychotic agents are known to cause adverse cutaneous reactions in approximately 5% of the individuals for whom they are prescribed. The majority of adverse cutaneous events are benign and easily treated, and do not place the patient at a serious health risk. However, these adverse events may impact on compliance so discussing strategies with the patient to avoid potential adverse cutaneous effects will improve compliance. The most frequently reported cutaneous adverse effects of antipsychotic medications include: exanthematous eruptions, skin pigmentation changes, photosensitivity, urticaria and pruritus. Only a small percentage of adverse cutaneous reactions are life threatening. The most important step in minimizing morbidity is prompt recognition of severe drug reactions with withdrawal of the causative medication. If a skin eruption occurs in an outpatient setting, it is generally advisable to discontinue the drug and to consider switching to another class of agent. If the reaction is mild, and the therapeutic benefits far exceed the risks of the symptomatic treatment, then the antipsychotic agent may be continued.

Liver function tests during treatment with antipsychotic drugs: a case series of 23 patients

Atypical antipsychotics represent a new class of medication for the treatment of schizophrenia and their use is associated with a reduction of neurological side effects. This article reports the result of the systematic clinical and biological supervision of hepatic enzymes on 23 schizophrenic inpatients treated by atypical antipsychotic during 2 weeks at Days 1 (D1), 7 (D7), and 14 (D14) in a naturalistic study during 6 months. The drug administrated was limited to four medications--risperidone, amisulpride, olanzapine, and clozapine--but other psychotropic agents were prescribed. Six cases of biological cytolytic hepatitis were observed. Due to the numerous risk factors and the frequency of "routine" conditions, careful supervision of the hepatic function is needed to prevent this kind of side effect.

Drug-induced liver disease

Although the year 2001 did not see any prescription drugs withdrawn because of drug-induced liver disease, the US Food and Drug Administration requested that dietary supplements containing comfrey be taken off the market because of the danger of hepatic injury. The Food and Drug Administration remains very involved in the process by which drug-induced liver disease can be detected early in drug development and in the determination of how best to prevent hepatotoxicity after drug approval. A workshop on drug-induced liver disease cosponsored by the Food and Drug Administration, the Pharmaceutical Research and Manufacturers Association, and the American Association for the Study of Liver Diseases was held in Washington, DC, in February 2001, and the resulting white paper outlined several areas for research. A number of agents were newly described as causing various forms of liver injury, and several others had drug-induced liver disease confirmed by additional reports. Several investigators dealt with the difficulties inherent in establishing causality of drug-induced liver disease and the potential negative consequences of wrongly attributing hepatotoxicity to a particular agent. In one recent series, more than half the instances of alleged drug-induced liver disease were found to have other causes, often leading to a delay in the actual diagnosis and appropriate management. Case reports in particular were often misleading. Although several drug assessment scales have been developed, none appears to be foolproof.