Biomedical subjects

Neil H Shear

Publications and source records attributed to Neil H Shear.

41 records · Page 3Linked to original sources

PubMed2002

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.

Adult↗

PubMed2002

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.

Child↗

PubMed2002

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.

Antineoplastic Agents↗

PubMed2002

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.

Administration, Oral↗

PubMedDate not supplied

Integrating biologic agents into management of moderate-to-severe psoriasis: a consensus of the Canadian Psoriasis Expert Panel. February 27, 2004.

BACKGROUND: Approximately 2% of people worldwide have psoriasis, with as many as 1 million people with psoriasis in Canada alone.1,2 The severity of psoriasis ranges from mild to severe. It can lead to substantial morbidity and psychological stress and have a profound negative impact on patient quality of life.3,4 Although available therapies reduce therapies reduce the extent and severity of the disease and improve quality of life,3 reports have indicated a patient preference for more aggressive therapy and a dissatisfaction with the effectiveness of current treatment options.5 OBJECTIVE: A Canadian Expert Panel, comprising Canadian dermatologists, convened in Toronto on 27 February 2004 to reach a consensus on unmet needs of patients treated with current therapies and how to include the pending biologic agents in and improve the current treatment algorithm for moderate-to-severe psoriasis. Current treatment recommendations suggest a stepwise strategy starting with topical agents followed by phototherapy and then systemic agents.3,6,7 The Panel evaluated the appropriate positioning of the biologic agents, once approved by Health Canada, for the treatment of moderate-to-severe psoriasis. METHODS: The Panel reviewed available evidence and quality of these data on current therapies and from randomized, controlled clinical trials.8-14 Subsequently, consensus was achieved by small-group workshops followed by plenary discussion. RESULTS: The Panel determined that biologic agents are an important addition to therapies currently available for moderate-to-severe psoriasis and proposed an alternative treatment algorithm to the current step wise paradigm. CONCLUSION: The Panel recommended a new treatment algorithm for moderate-to-severe psoriasis whereby all appropriate treatment options, including biologic agents, are considered together and patients' specific characteristics and needs are taken into account when selecting the most appropriate treatment option.

Alefacept↗