Objective psychological measurement and clinical assessment of anxiety in adverse drug reactions

BACKGROUND

A confounding factor in the diagnosis of adverse drug reactions (ADRs) is the psychological state of the patient. Patients with underlying anxiety and related disorders may present with psychogenic reactions, which involve physiologic responses originating from psychological, rather than organic factors.

OBJECTIVE

To examine the contribution of anxiety and related disorders to adverse drug events.

METHODS

Participants from an adverse drug reaction clinic completed the Trauma Symptom Checklist-40 (TSC-40), a 40-item questionnaire consisting of six subscales: anxiety, depression, dissociation, sexual abuse trauma index (SATI), sexual problems, and sleep disturbance. Physicians assessed the likelihood that adverse events were due to anxiety or drug(s) by providing an anxiety score (0 to 10) and an ADR score (0 to 10), respectively, for each participant.

RESULTS

Patients clinically assessed as having "high anxiety" (anxiety score 7-10 and ADR score 0-3; n = 11) scored higher than patients clinically assessed as having a "true ADR" (anxiety score 0-3 and ADR score 7-10; n = 19) on the TSC-40 total (P = 0.006) as well as anxiety (P = 0.012), depression (P = 0.007), and SATI subscales (P = 0.016).

CONCLUSION

This study is the first to use a validated psychological measurement to indicate that a substantial percentage of reported adverse drug events may in fact be a manifestation of underlying anxiety and/or related disorders. We suggest that mechanisms of symptom generation may be analogous to those operative in idiopathic environmental intolerance.

Evaluation of the Extent of Under-Reporting of Serious Adverse Drug Reactions

INTRODUCTION

Toxic epidermal necrolysis (TEN) is a life-threatening adverse drug reaction (ADR) that is primarily the result of drug exposure (incidence 0.4-1.3 per million person-years). Life-threatening ADRs such as TEN should be reported to ADR monitoring programmes, which collect reports for suspected ADRs and alert the public and medical practitioners to new drug hazards. In Canada, reports are made to the Canadian Adverse Drug Reaction Monitoring Program (CADRMP).

OBJECTIVE

To examine the extent of under-reporting for TEN in Canada.

DESIGN

A retrospective case series design was used to collect all TEN cases for the period January 1995 to December 2000.

METHODS

The CADRMP and 22 burn centres across Canada were contacted for all TEN patients treated during the specified time period. PATIENT GROUPS STUDIED: The study population consisted of patients admitted to burn treatment sites across Canada, patient cases reported to the CADRMP and patient cases recorded by the Canadian Institute for Health Information (CIHI) hospital discharge summaries as the International Classification of Diseases Version 9 Clinical Modification (ICD-9-CM) code 695.1.

RESULTS

Twenty-five TEN cases (six fatal) were reported to CADRMP from January 1995 to December 2000. During this period, 14 (63.6%) burn treatment sites reported admission of 250 TEN cases. Hospital discharge summaries using the ICD-9-CM code 695.1 indicated that 4349 cases were admitted to hospital during this time period and it was estimated that 15.5% (n = 674) of these cases were TEN. Using the burn facility data as the denominator, 10% (25 of 250) of TEN cases were reported to CADRMP. Using CIHI data as a denominator, only 4% (25 of 674) of TEN cases were reported to CADRMP.

CONCLUSIONS

There is serious under-reporting of TEN. Lack of reporting of life-threatening ADRs can compromise population safety. There is a need to increase awareness of ADR reporting programmes.

Clinical pharmacology consultations: consultation requests may be misleading -- an organized approach to drug-induced hepatitis

The present case report describes a consultation with the Clinical Pharmacology Consultation Service at the Sunnybrook & Women's College Health Sciences Centre, Toronto, Ontario, for drug-induced hepatitis in a patient with multiple drug exposures. The original question to be addressed was whether dalteparin was responsible for an acute rise in liver transaminases. The approach involved establishing a best possible diagnosis of the adverse event, obtaining a comprehensive history of drug exposure and evaluating the possible contributory role of alternate etiologies supported by a literature search. On balance, based on temporal relationships and previous case reports, ranitidine was considered to be the most likely causal agent. The initial consultation request was to investigate the likelihood that daltaperin caused hepatitis; however, a systematic and comprehensive approach led to the conclusion that it was more likely to be ranitidine-induced hepatitis.

Cytotoxic T lymphocyte reactivity to gp100, MelanA/MART-1, and tyrosinase, in HLA-A2-positive vitiligo patients

Vitiligo is a common depigmentation disorder thought to result from autoimmune destruction of melanocytes. Recent studies suggest a role for cell-mediated immune responses to melanocyte differentiation antigens, including gp100, MelanA/MART-1, and tyrosinase, in vitiligo pathogenesis. This study investigated T cell reactivity to MelanA/MART-1, tyrosinase, and gp100, in HLA-A2-positive patients with vitiligo. Melanocyte-specific T cell responses were measured ex vivo via enzyme-linked immunospot assay following stimulation with MelanA/MART-1, tyrosinase, and modified gp100 epitopes. Antigen-specific T lymphocyte reactivity to gp100 peptides was seen in 15 of 17 (88%) patients, with many demonstrating very high reactivity at levels comparable with those observed with common recall antigens. Reactivity to gp100 was noted to be associated with disease activity. Antigen-specific T lymphocyte reactivity to MelanA/MART-1 and tyrosinase peptides was not observed ex vivo in our patients, and only one patient demonstrated responses to MelanA/MART-1 and tyrosinase peptides following in vitro re-stimulation. Our findings implicate T cell reactivity to gp100 in patients with active disease and support the concept of an immunopathologic mechanism in vitiligo, in which cell-mediated responses to normal melanocyte antigens play a crucial part.

Safety of celecoxib in individuals allergic to sulfonamide: a pilot study

OBJECTIVE

To evaluate cross reactivity between sulfonamide antimicrobials and celecoxib in patients with histories of allergies to sulfonamide antimicrobials.

METHODS

Immunocompetent patients with a history of sulfonamide antimicrobial allergy who were being considered for therapy with celecoxib were prospectively enrolled. Sulfamethoxazole and trimethoprim skin prick and intradermal testing and/or an in vitro lymphocyte toxicity assay were performed. If skin testing was negative, an oral challenge with sulfamethoxazole and trimethoprim was performed. Oral challenges with celecoxib were administered to all patients.

RESULTS

Twenty-eight immunocompetent patients (26 female; mean age 60 years) were evaluated. History of sulfonamide antimicrobial allergy included urticaria (n = 7), cutaneous eruptions (n = 9), and other (n = 12). Four of the 28 patients who were skin prick tested were positive to sulfamethoxazole and two of the ten patients who underwent in vitro testing were positive to sulfamethoxazole. All 28 patients were administered celecoxib and tolerated the medication. Phone call follow up in 25 patients disclosed that 15 patients continued to take celecoxib, while five patients did not take celecoxib following the oral challenge, and five discontinued celecoxib due to adverse effects, lack of drug efficacy or physician preference.

CONCLUSIONS

Confusion exists regarding the potential for cross reactivity between sulfonamide antimicrobials and other sulfonamide-containing compounds. The six sulfonamide-allergic patients tolerated celecoxib uneventfully. This pilot study supports the hypothesis that the potential for cross-reactivity between celecoxib and sulfonamide antimicrobials appears to be low. However, further investigations are required to confirm this.

Reactive metabolites and adverse drug reactions: clinical considerations

Idiosyncratic reactions can affect many different organ systems, either as -an isolated event (e.g., hepatitis) or as part of a syndrome (e.g., drug hypersensitivity syndrome). Formation of reactive metabolites of drugs in conjunction with a decreased ability for detoxification is believed to be the initiating step in many idiosyncratic reactions. The drug hypersensitivity syndrome, defined by the presence of fever, rash and internal organ involvement, is estimated to occur in approx 1 in 1000 to 1 in 10,000 exposures with drugs such as anticonvulsants sulfonamide antibiotics, allopurinol, and dapsone. Symptoms usually start within 2-8 wk of drug initiation. Serum sicknesslike reaction, most frequently found after 7-14 d of drug exposure, is distinguished by a fever, cutaneous eruption and arthralgias. Medications such as cefaclor, minocycline and bupropion are most frequently implicated in this reaction. In contrast, drug-induced lupus can occur l-2 yr after initiation of medication. Drug-induced lupus is characterized by musculoskeletal complaints and fever and weight loss. Drugs most commonly associated with drug-induced lupus include procainamide, hydralazine, chlorpromazine, isoniazid, and minocycline. Management of patients who develop idiosyncratic reactions includes discontinuation of the implicated drug, initiation of corticosteroids (when appropriate), and symptomatic relief as required. Internal organ involvement, which may initially be asymptomatic, should be monitored. Confirmatory or diagnostic tests are not readily available in most areas, except for research purposes.

Drug eruptions: approaching the diagnosis of drug-induced skin diseases

Adverse drug reactions are a major problem in drug therapy, and cutaneous drug reactions account for a large proportion of all adverse drug reactions. Cutaneous drug reactions are also a challenging diagnostic problem since they can mimic a large variety of skin diseases, including viral exanthema, collagen vascular disease, neoplasia, bacterial infection, psoriasis, and autoimmune blistering disease, among others. Furthermore, determining that a particular medication caused an eruption is often difficult when the patient is taking multiple drugs. In this review, we will describe and illustrate a thoughtful, comprehensive, and clinical approach to the diagnosis and management of adverse cutaneous drug reactions. A morphologic approach to drug eruption includes those that are classified as maculopapular, urticarial, blistering or pustular with or without systemic manifestations. Exanthematous drug eruptions, drug hypersensitivity syndrome, urticaria and angioedema, serum sickness-like reactions, fixed drug eruptions, drug-induced autoimmune blistering diseases, Stevens-Johnson syndrome, toxic epidermal necrolysis, drug-induced acne, acute generalized exanthematous pustulosis, lichenoid drug eruptions and photosensitivity eruptions will be discussed.

The kidney--the body's playground for drugs: an overview of renal drug handling with selected clinical correlates

A greater understanding of transport mechanisms contributing to renal drug handling may be useful in predicting drug clearance and drug interactions. Renal clearance is a dynamic process expressed as the sum of the rates of glomerular filtration and tubular secretion minus the rate of tubular reabsorption. Because the transport of drugs is often against a concentration gradient, renal secretion is mostly an active process involving a variety of transporter mechanisms. Discoveries from molecular biology techniques and gene 'knock-out' experiments have identified a variety of renal tubular proteins responsible for the transport of organic cations, organic anions, neutral and cationic hydrophobic compounds, anionic conjugates and specific agents such as prostaglandins. The discovery of a P-glycoprotein (P-gp) transporter at the apical membrane of renal tubular cells is particularly important. By elucidating compounds that act as substrates, inhibitors or inducers of transport proteins, pharmacologists and clinicians may better understand renal drug clearance. This paper provides a brief overview of several identified renal transport proteins including organic anion transporters, organic cation transporters, ATP-dependent transporters (multidrug resistance [P-gp] and multi-drug resistance associated protein), nucleoside transporters (sodium-dependent purine nucleoside transporter and concentrative nucleoside transporter 1) and peptide transporters. A special focus on known P-gp-mediated drug interactions is included to demonstrate the clinical relevance of transporter protein science. At the patient level, this may lead to novel approaches to alter in vivo pharmacokinetics and improve drug safety through a greater understanding of toxic substrate clearance and drug interactions.

Erythema multiforme, Stevens-Johnson syndrome and toxic epidermal necrolysis in children: a review of 10 years' experience

OBJECTIVE

To review 10 years' experience in a tertiary care paediatric hospital of erythema multiforme (EM), Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). In addition, to apply a recently described classification system for EM, SJS and TEN in children.

DESIGN

Retrospective study of all children with a discharge diagnosis of EM, SJS or TEN over a 10-year period.

SETTING

A university tertiary care paediatric hospital.

PATIENTS

Sixty-one paediatric patients with a discharge diagnosis of EM, SJS or TEN.

MAIN OUTCOME MEASURES

Epidemiology, laboratory features, causative factors, treatment methods, complications and mortality of EM, SJS and TEN in this group of patients. Comparison of correlation with aetiology of old and new classification systems in a paediatric population.

RESULTS

Mucous membrane involvement was documented in 61% of patients. Ocular involvement was seen in 39%. Complications occurred in 21% cases, all of whom had SJS or TEN. Only one patient died as a result of their skin condition. Corticosteroids were used in 18% of cases; 95% of whom had a discharge diagnosis of SJS or TEN. The drugs most commonly identified as aetiological agents were sulphonamides and penicillins (26% each). The most frequently implicated infectious agent was herpes simplex virus (19.7%). Classification of study cases according to Bastuji-Garin et al. indicates a strong trend toward bullous EM cases being attributable to infection and SJS/TEN cases to drugs. There was no such clear trend with respect to aetiology when diagnosis was done without the classification system.

CONCLUSION

EM, SJS and TEN rarely cause mortality but significant morbidity is seen. Infectious agents, particularly herpes simplex virus, and drugs, especially the sulphonamides and penicillins, are the most common aetiological agents. The classification system proposed by Bastuji-Garin et al. correlates better with aetiology than the practice that preceded it.

Lupus-associated toxic epidermal necrolysis: a novel manifestation of lupus?

BACKGROUND

Toxic epidermal necrolysis is an acute mucocutaneous reaction characterized by extensive cutaneous and mucosal sloughing and systemic involvement. It is generally associated with drug ingestion.

OBJECTIVE AND METHODS

We describe 2 patients who developed typical clinical and histopathologic features of toxic epidermal necrolysis with unusual subacute progression, absence of systemic involvement or high-risk drug ingestion, and features of lupus erythematosus.

CONCLUSION

We propose that this constellation of features represents a new entity not previously described. This entity may represent a more severe variant of Rowell's syndrome or, alternatively, a novel manifestation of lupus erythematosus

Cutaneous cleansers

Skin cleansers may be an important adjunct to the regimen of those who use cosmetics, have sensitive or compromised skin, or utilize topical therapies. Cleansers emulsify dirt, oil and microorganisms on the skin surface so that they can be easily removed. During cleansing, there is a complex interaction between the cleanser, the moisture skin barrier, and skin pH. Cleansing, with water soap or a liquid cleanser, will affect the moisture skin barrier. Soap will bring about the greatest changes to the barrier and increase skin pH. Liquid facial cleansers are gentler, effecting less disruption of the barrier, with minimal change to skin pH, and can provide people with a cleanser that is a combination of surfactant classes, moisturizers and acidic pH in order to minimize disruption to the skin barrier.

Confirming false adverse reactions to drugs by performing individualized, randomized trials

One-patient, randomized, double-blind, controlled trials (N-of-1 RCTs) have traditionally been used to assess the efficacy of treatment. At the Drug Safety Clinic, Toronto, this methodology is used to evaluate adverse effects related to medication use, specifically when the symptoms are vague and are in response to more than one medication. Two patients are described with histories of drug allergies to multiple medications; as well, guidelines for conducting N-of-1 trials are summarized. The first patient had a history of prolonged periorbital and generalized weakness lasting up to one week after exposure to a variety of drugs. Because of the ambiguous results of local anesthetic skin testing, an N-of-1 trial was performed using lidocaine without preservative. Two short-lived episodes of blepharospasm and lethargy were observed with placebo; no subjective or objective reaction occurred with active drug. The second patient had a history of prolonged weakness and drowsiness after exposure to many medications; she had been told that she was allergic to all drugs with a benzene ring. During the first N-of-1 trial, generalized weakness was observed with 10 mg of dimenhydrinate and all four placebo doses. During the second N-of-1 challenge using codeine, no unwarranted reactions occurred with either active or placebo drug. Traditional testing of these patients to disprove the clinical symptoms is often difficult because of the anxiety level associated with the patients' past experiences. N-of-1 trials provide a useful alternative for the management of patients with nonspecific symptomatology attributed to drug ingestion.

Monitoring adverse drug reactions to sulfonamide antibiotics in human immunodeficiency virus-infected individuals

Patients infected with the human immunodeficiency virus (HIV) are at higher risk for adverse drug reactions from trimethoprim-sulfamethoxazole (TMP-SMX) than the HIV-negative population. Studying the HIV-positive population the authors aimed to validate the predictive and diagnostic value of the lymphocyte toxicity assay (LTA) for adverse drug reactions. Patient lymphocytes were analyzed for toxicity to SMX and TMP. Of 35 enrolled HIV patients, 18 had TMP-SMX hypersensitivity syndrome reaction (HSR); 10 tolerated the drug; and 5 had never received the drug. When cases with HSR were compared with controls that tolerated the drugs, cytotoxicity was higher for cases: 29.5% +/- 10.1% versus 19.3% +/- 11.2% for SMX (P < 0.022) and 25.0% +/- 11.9% versus 16.3% +/- 11.0% for TMP (P < 0.04). The authors' proposed threshold value for assigning positive results for TMP and SMX hypersensitivities was 22.5%. The LTA has a strong potential for use as a diagnostic tool to assess TMP-SMX hypersensitivity in HIV-infected individuals. Larger patient populations, as well as in vitro studies are needed to further address the reasons for elevated results in immunocompromised patients and to validate the usefulness of the test.

Drug interactions: Proteins, pumps, and P-450s

The two major concerns in drug safety are adverse drug reactions and drug interactions. When multiple drug therapies are prescribed, drug interactions become an important consideration for patients and physicians. The life of a drug is reviewed with emphasis on absorption, distribution, metabolism, and excretion. Pharmacokinetic and pharmacodynamic mechanisms for drug interactions are reviewed. The contributions of P-glycoprotein, pharmacogenetic variation, and genetic polymorphisms to drug interactions are highlighted. Prediction of drug interactions is possible with knowledge of which agents are likely to cause alterations in drug metabolism. (J Am Acad Dermatol 2002;47:467-84.)

LEARNING OBJECTIVE

At the conclusion of this learning activity, participants should have an understanding of the life of a drug. This knowledge should help predict important potential drug interactions.

Kinetics of serum cytokines reflect changes in the severity of chronic hepatitis C presenting minimal fibrosis

Our aims were to measure the kinetics of serum tumour necrosis alpha (TNF-alpha) and transforming growth factor beta (TGF-beta) levels as markers of progression of disease in nontreated chronic hepatitis C virus (HCV)-infected patients with minimal or no fibrosis and minimal histology activity index (HAI) scores. Our study group consisted of 56 patients diagnosed with minimal (1) or no fibrosis (0) and minimal HAI (0-1) on their first biopsy as defined by Knodell and METAVIR scores. We compared their initial (entry of study) cytokine levels with a group of 103 HCV controls with minimal (0-1) to mild fibrosis (0-3) and mild HAI (5.5). Serum TNF-alpha and TGF-beta levels were measured by enzyme-linked-immunosorbent-assay. A significant difference was seen in TNF-alpha levels at baseline in the study group vs. controls. Regardless of their HAI, there was a correlation between TGF-beta and degree of fibrosis. As shown by their biopsies, during the 3 years (from entry to follow up), many of the patients that initially had minimal fibrosis progressed to higher degree of fibrosis. This progression is paralleled by an increase in TGF-beta levels when comparing initial and follow-up levels. In conclusion, serum TNF-alpha reflects the progression of inflammation as seen in liver biopsies and TGF-beta reflects the degree of fibrosis in HCV patients.

Role of cytokines in the assessment of the severity of chronic hepatitis C and the prediction of response to therapy

AIMS

(i) To characterize serum levels of pro/anti-inflammatory cytokines in non-cirrhotics with hepatitis C; (ii) to correlate levels of these cytokines with degree of disease at baseline; and (iii) to characterize the immuno-modulatory effects of therapy with response.

METHODS

We studied 103 patients that were part of randomized, controlled, clinical trials. Serum cytokines were measured using enzyme-linked immunosorbent assay.

RESULTS

Using standard therapy in the presence and absence of ribavirin, the sustained responders had lower baseline tumor necrosis alpha (TNF-alpha) levels as compared to relapsed responders and non-responders. In patients receiving pegylated therapy, the degree of inflammation as determined by histology was paralleled by high TNF-alpha levels at baseline. In pegylated combination therapy with high dose ribavirin, lower levels of TNF-alpha, transforming growth factor beta (TGF-beta) and fibrosis scores were seen when comparing baseline with follow up. In sustained responders, regardless of therapy, the histological activity scores were lower at follow up as compared to baseline.

CONCLUSIONS

Pegylated combination therapy reduces and sustains TNF-alpha levels and liver inflammation as shown by the histological activity index. In addition, it is able to reduce fibrosis as judged both by TGF-beta levels and fibrosis scores as compared to standard therapy.

Ethanol signals for apoptosis in cultured skin cells

Ethanol is commonly used in cosmetic and pharmaceutical preparations. To test whether ethanol may cause apoptosis in skin cells, we treated A431 epidermoid skin cells and neonatal human primary skin cells with different concentrations of ethanol, for different time periods. Ethanol was toxic to cells in both a dose- and time-dependent manner and increased the percentage of cells undergoing apoptosis. Treatment of cells with 40 and 100 mM ethanol increased release of the proinflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) into culture medium and increased its expression in cells. The TNF-alpha was toxic to A431 epidermoid skin cells at concentrations similar to those released by cells on exposure to ethanol. Ethanol-treated cells examined by electron microscopy showed organelle damage, condensed chromatin, and apoptotic bodies. Therefore, even at low concentrations, ethanol may induce apoptosis in skin cells by enhancing the effects of TNF-alpha.

Kinetics of serum cytokines reflect changes in the severity of chronic hepatitis C presenting minimal fibrosis

Our aims were to measure the kinetics of serum tumour necrosis alpha (TNF-alpha) and transforming growth factor beta (TGF-beta) levels as markers of progression of disease in nontreated chronic hepatitis C virus (HCV)-infected patients with minimal or no fibrosis and minimal histology activity index (HAI) scores. Our study group consisted of 56 patients diagnosed with minimal (1) or no fibrosis (0) and minimal HAI (0-1) on their first biopsy as defined by Knodell and METAVIR scores. We compared their initial (entry of study) cytokine levels with a group of 103 HCV controls with minimal (0-1) to mild fibrosis (0-3) and mild HAI (5.5). Serum TNF-alpha and TGF-beta levels were measured by enzyme-linked-immunosorbent-assay. A significant difference was seen in TNF-alpha levels at baseline in the study group vs. controls. Regardless of their HAI, there was a correlation between TGF-beta and degree of fibrosis. As shown by their biopsies, during the 3 years (from entry to follow up), many of the patients that initially had minimal fibrosis progressed to higher degree of fibrosis. This progression is paralleled by an increase in TGF-beta levels when comparing initial and follow-up levels. In conclusion, serum TNF-alpha reflects the progression of inflammation as seen in liver biopsies and TGF-beta reflects the degree of fibrosis in HCV patients.

Task force report: future research needs for the prevention and management of immune-mediated drug hypersensitivity reactions

Immune-mediated drug hypersensitivity reactions (IDHR) have a significant impact on clinical practice, drug development, and public health. However, research to understand IDHR mechanisms and to develop diagnostic and predictive tests has been limited. To stimulate more research, a task force with representatives from the key stakeholders (research clinicians, regulatory scientists, and immunotoxicologists from the pharmaceutical industry) was assembled to identify critical data gaps and opportunities and to make recommendations on how to overcome some of the barriers to IDHR research and address research needs. It is hoped that this report will act as a springboard for future discussions and progress toward increased funding and development of organizational structures for IDHR research.