Biomedical subjects
Publications and source records attributed to N H Shear.
Spironolactone therapy is uncommonly associated with cutaneous side effects. We describe a patient who developed a maculopapular eruption while on spironolactone with a positive reaction upon rechallenge with the drug. The cutaneous associations of spironolactone in the English literature have been reviewed.
OBJECTIVE: To report a case of a possible hypersensitivity reaction induced by metronidazole. CASE SUMMARY: An Asian woman with a history of recurrent vaginitis had previously developed localized erythema while on intravaginal metronidazole and nystatin. While receiving oral metronidazole for treatment of a current bacterial vaginosis, she developed chills, fever, generalized erythema, and a rash within 60 minutes of the first dose. Treatment with diphenhydramine was instituted. The following day while in the hospital, the patient's condition worsened; she experienced shortness of breath and increased edema of the extremities. Methylprednisolone was administered with diphenhydramine and her condition improved over the next 5 days. The patient's vaginitis was treated with gentian violet and she was discharged on a tapering dosage of prednisone. DISCUSSION: Metronidazole-induced cutaneous reactions and systemic hypersensitivity reactions are reviewed. Alternatives to metronidazole and other potential cross-reactive drugs are suggested for the treatment of recurrent vaginitis. CONCLUSIONS: Although the patient's initial reaction to metronidazole represented a rare event, written documentation and communication in the patient's native language may have prevented the subsequent severe hypersensitivity reaction.
The last decade has witnessed remarkable advances in the therapy for cutaneous fungal diseases. These will have a major impact on the choice of antifungal therapy. To understand these advances traditional therapies for fungal diseases, the polyenes, griseofulvin, older topical agents and the older azoles, will be reviewed first. Part II will focus on recent advances.
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BACKGROUND AND DESIGN: To conduct a prospective case-control study about causative factors of severe bullous erythema multiforme, Stevens-Johnson syndrome, and toxic epidermal necrolysis, we needed to define criteria for classifying the cases and standardize the collection of data so that cases could be reliably diagnosed according to this classification. Based on review of case histories and photographs of patients, a group of experts proposed a classification based on the pattern of erythema multiforme-like lesions (categorized as typical targets, raised or flat atypical targets, and purpuric macules) and on the extent of epidermal detachment. An atlas illustrating this classification that included photographs and schematic drawings was developed. We compared the evaluations of 28 cases by four nonphysicians relying on the atlas with the evaluations of the same cases by five experts not using the atlas to determine the usefulness of this atlas for classifying cases according to our nosologic schema. RESULTS: The following consensus classification in five categories was proposed: bullous erythema multiforme, detachment below 10% of the body surface area plus localized "typical targets" or "raised atypical targets"; Stevens-Johnson syndrome, detachment below 10% of the body surface area plus widespread erythematous or purpuric macules or flat atypical targets; overlap Stevens-Johnson syndrome-toxic epidermal necrolysis, detachment between 10% and 30% of the body surface area plus widespread purpuric macules or flat atypical targets; toxic epidermal necrolysis with spots, detachment above 30% of the body surface area plus widespread purpuric macules or flat atypical targets; and toxic epidermal necrolysis without spots, detachment above 10% of the body surface area with large epidermal sheets and without any purpuric macule or target. Using the atlas, the nonexperts showed excellent agreement with the experts. CONCLUSION: This study suggests that an illustrated atlas is a useful tool for standardizing the diagnosis of acute severe bullous disorders that are attributed to drugs or infectious agents. Whether the five categories proposed represent distinct etiopathologic entities will require further epidemiologic and laboratory investigations.
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The clinician plays a key role in the detection and diagnosis of adverse drug reactions (ADRs). The diagnosis of ADRs, however, is a complex task. In the past, there were no systematically applied diagnostic criteria for ADRs, no formal methods of case analysis, no standardized epidemiologic approaches, and a limited knowledge of mechanisms. This resulted in the overdiagnosis of ADRs, which has negative consequences such as limiting treatment options. Recently, there have been various improvements in the diagnosis of ADRs, such as the development of standardized decision aids and of in vitro diagnostic tests. This article briefly reviews some of this knowledge, discusses the role of in vivo and in vitro rechallenge, and summarizes a probabilistic approach for collecting relevant information and diagnosing ADRs. The intention is to increase awareness of the different approaches for diagnosing ADRs as well as to stimulate researchers to continue to collect pharmacoepidemiologic information, study the pharmacologic, immunologic, and genetic factors involved in the pathogenesis of drug reactions, and develop and test new diagnostic instruments under various clinical conditions.
Inherited defects in detoxification of reactive metabolites of drugs predispose patients to "hypersensitivity" reactions. Covalent interaction of metabolites with cell macromolecules leads to cytotoxic and immunologic outcomes, manifested clinically by multisystem syndromes with variable organ involvement. Hypothyroidism developed in 5 of 202 patients (age range, 1 to 81 years) we investigated for hypersensitivity reactions to anticonvulsants or sulfonamides shortly after their reaction. None had previous personal or family histories of autoimmune disease. All had low thyroxine levels, elevated levels of thyroid stimulating hormone, and autoantibodies including antimicrosomal antibodies. Patients were 2 to 18 years of age at presentation, and two were male. All returned to a euthyroid state within a year of presentation, and all remain well. The demographics, clinical presentation, and course of the patients is atypical of idiopathic lymphocytic thyroiditis. We investigated the pathogenesis of thyroid toxicity using the hydroxylamine metabolite of sulfamethoxazole as a model. The hydroxyalmine was toxic to thyroid cells in vitro, which did or did not express thyroid peroxidase activity, whereas the parent sulfonamide was toxic only to cells with active thyroid peroxidase. The purified enzyme converted sulfamethoxazole to the hydroxylamine. Formation of reactive drug metabolites by thyroid peroxidase in a host who is genetically unable to detoxify the metabolites may lead directly to cytotoxicity. Covalent binding to macromolecules, including thyroid peroxidase, also may lead to expression of neoantigens and formation of autoantibodies. Patients who have sustained hypersensitivity reactions to drugs should be investigated for possible involvement of the thyroid.
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Sorbinil is a hydantoin aldose reductase inhibitor that has shown promise as therapy for patients with diabetic complications such as neuropathy and retinopathy. However, as many as 10% of patients receiving sorbinil have had adverse reactions characterized by fever, skin rash, and myalgia. Our previous studies of phenytoin suggested that susceptibility to reactions might result from an inherited detoxification defect. We did the current study to determine if sorbinil is metabolized to reactive intermediates and if cells from patients with a history of a reaction to sorbinil are appropriate for the in-vitro investigation of susceptibility. Microsome-generated metabolites of sorbinil (50 microM) were toxic to normal peripheral blood lymphocytes (7.9% +/- 0.3% dead cells [mean +/- SE]). Toxicity was increased in the presence of an epoxide hydrolase inhibitor (17.5% +/- 0.3% dead cells) and abolished by an inhibitor of cytochrome P-450. In contrast to cells from healthy controls and diabetics who tolerated sorbinil (7.9% +/- 0.7% and 7.8% +/- 0.4% dead cells, respectively), cells from the six patients who had sorbinil reactions showed significantly increased toxicity from metabolites of sorbinil and phenytoin (19.7% +/- 2.3% dead cells, P less than 0.001). Cells from three patients who had reactions to phenytoin were similarly sensitive to sorbinil metabolites (23.4% +/- 0.3% dead cells). We conclude that sorbinil is oxidatively metabolized to a potentially toxic intermediate. Certain patients may be at increased risk for developing hypersensitivity reactions. Development of this important new drug has been hampered by uncommon but potentially severe reactions. An increased understanding of the steps involved in the development of adverse reactions could lead to screening tests or to the development of safer compounds.
Delayed hypersensitivity reactions are among the most severe adverse effects of the sulfonamides in current clinical use. These reactions appear to occur because of differences in the metabolism and detoxification of reactive metabolites of the sulfonamides. N-Acetylation is a major metabolic pathway for the sulfonamides. Slow acetylation phenotype might be a risk factor for the development of these reactions. We determined the acetylation phenotype of 21 patients who had suffered hypersensitivity reactions to the sulfonamides. There were 11 females and 10 males in the group, with a mean age of 15 years (age range, 1.8 to 50 years). Their acetylator phenotype was determined by determining the ratio of urinary caffeine metabolites (1-methylxanthine to 5-amino-6-formylmethyluracil after an oral dose of 50 mg caffeine). Nineteen (90%) of the patients were slow acetylators compared to a 55% incidence of slow acetylators in a race-matched control population (p less than 0.008). This suggests that a slow acetylator phenotype is a risk factor for the development of sulfonamide hypersensitivity reactions and provides further support for the role of imbalances in genetically determined pathways of metabolism and detoxification of the sulfonamides in the pathogenesis of these reactions.
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On the basis of a literature review and eight cases of our own, we analyzed 37 cases of Mycoplasma pneumoniae (MP) infection and Stevens-Johnson syndrome (SJS). Our clinical and laboratory findings do not differ from those reported in the literature for MP infection with no exanthem or for SJS of various etiologies. Eighty percent of the children presented with symptoms of upper respiratory tract infection (URTI) (cough, fever, sore throat, malaise, headache), with a mean of 10 days (range 1 to 30) before skin rash broke out. Skin manifestations occurred in 94.2% of the patients after 3 to 21 days (mean 10.3 days) of fever. The exanthem, composed predominantly of maculopapular and vesicular, was distributed chiefly on the trunk and extremities and lasted less than 14 days in 87.8% of the patients. Stomatitis was observed in 91.6% of the patients and conjunctivitis in 50%. No consistent pattern seems to emerge by which one could predict the existence of MP infection causing SJS. The complications of SJS associated with MP seem less frequent (2.7%) and much less severe than in cases where SJS arises from other reported causes. Because coincidence cannot be excluded from the assessments of the degree and rate of improvement for the few patients treated with corticosteroid, from the low frequency of complications, and from the mortality rate of zero in this series of patients, the use of corticosteroids for SJS associated with MP infection is questionable.
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STUDY OBJECTIVE: To determine whether differences in in-vitro detoxification of sulfonamide-reactive metabolites can be detected among the lymphocytes from controls, patients with sulfonamide hypersensitivity reactions, and patients with nonhypersensitivity reactions to the sulfonamide agents. DESIGN: In-vitro toxicity assay on lymphocytes. SETTING: Clinics for adverse drug reactions in an adult and pediatric tertiary care center. PATIENTS: Peripheral blood lymphocytes were obtained from 46 normal volunteers and 76 patients referred to the clinic for assessment of adverse drug reactions to sulfonamide agents. Thirty-one patients had clinical histories consistent with a diagnosis of hypersensitivity reaction, whereas 45 patients had clinical histories felt to be inconsistent with a diagnosis of hypersensitivity reaction. INTERVENTIONS: Lymphocytes were assayed with tetrazolium to determine toxicity from the hydroxylamine of sulfamethoxazole. MEASUREMENTS AND MAIN RESULTS: The lymphocytes from patients with a history of hypersensitivity reactions showed markedly increased toxicity across a tenfold-concentration toxicity-concentration curve compared with those from controls and patients with a history of nonhypersensitivity reactions. These differences were highly significant (P less than 0.01). No difference was found between the toxicity shown by the lymphocytes from controls and that shown by the lymphocytes from patients with a history of nonhypersensitivity reactions. CONCLUSIONS: Metabolic differences in the production and detoxification of reactive metabolites of sulfonamide agents are important determinants of hypersensitivity reactions to these agents. These results suggest that the hydroxylamine derivative of sulfamethoxazole may be a reactive metabolite mediating these reactions. Sulfonamide hydroxylamines are useful in the diagnosis and study of the pathogenesis of hypersensitivity reactions to sulfonamide agents.
We evaluated the causality of the association between intrauterine exposure to phenytoin and postnatal neuroblastoma using an in vitro lymphocyte toxicity assay for phenytoin-induced reactions in an unusual sibship. In addition, we investigated intrauterine phenytoin exposure in a case series of infants and children with neuroblastoma diagnosed over 17 years at our center. The response of lymphocytes from our index case with neuroblastoma exposed in utero to phenytoin was within the normal range, whereas the mother and a sibling with fetal hydantoin syndrome (FHS) exhibited an intermediate toxicity. None of the 188 cases of childhood neuroblastoma diagnosed between 1969 and 1988 had been exposed in utero to phenytoin, indicating that, statistically, the drug cannot be associated with neuroblastoma in more than two cases with this malignancy in our cohort, or in 1.5% of all cases of neuroblastoma. Although our data do not suggest an association between phenytoin in pregnancy and postnatal neuroblastoma, it is still possible that there is an increased risk for neuroblastoma in children with FHS.