Drug allergy--problems and strategies

Advances in Simple and Chiral-HPLC Methods for Antiallergic Drugs and Chiral Recognition Mechanism

Among many diseases, allergy appears to be a serious problem for human beings. Various forms of allergic disorders make people tense, leading to some other health issues. Many medications, including nonracemic and racemic ones, are used to treat this problem. It is important to have exact analysis strategies just to see any medication side effects, plasma profiles, and working efficiency. Therefore, efforts are made to review simple and chiral HPLC methods for antiallergic drugs; HPLC is the best analytical technique. The highlights in this article include the world scenario, causes of allergy, the effect of allergy on the economy, the mechanism of allergy in humans, classes of antiallergic drugs, simple drugs, chiral drugs, analysis by HPLC, and the chiral recognition mechanism. Moreover, attempts are also made to highlight the management of allergies and future perspectives.

Impact of Allergy and Resistance on Antibiotic Selection for Recurrent Urinary Tract Infections in Older Women

OBJECTIVES

To review the impact of antibiotic allergy and resistance in older women with recurrent urinary tract infections (RUTIs) as determinants for a suitable oral antibiotic treatment choice.

METHODS

A prospectively maintained database of women 65 years old and older with documented RUTIs (≥3 UTI/y) and trigonitis on cystoscopy was reviewed. Demographic data, known drug allergies, renal function, antibiotic susceptibility of most recent urine culture, allergy, or resistance to trimethoprim-sulfamethoxazole (TMP-SMX), fluoroquinolones, and nitrofurantoin were obtained.

RESULTS

From 2006 to 2014, 86 women with RUTIs met study criteria. Mean age was 77.9 ± 7.8, with 94% being Caucasian. An estimated glomerular filtration rate >30 mL/min was noted in 94%. The percentage of women allergic, resistant, or both allergic and resistant to TMP-SMX was 33%, 29%, and 15%, to fluoroquinolones was 14%, 34%, and 8.1%, or nitrofurantoin was 16%, 14%, and 5%, respectively. Twenty-eight percent (24 of 86) of women who were allergic and/or resistant to TMP-SMX and fluoroquinolones were sensitive to nitrofurantoin. Twenty percent (17 of 86) were allergic and/or resistant to all 3 antibiotics. Women who were allergic or resistant to TMP-SMX had a significantly higher number of other antibiotic resistances compared with women sensitive to TMP-SMX (4.9 ± 3.6 vs 2.1 ± 2.3; P < .0001). Similarly, women with fluoroquinolone allergy or resistance had significantly more antibiotic resistances than those who were fluoroquinolone sensitive (5.8 ± 3.5 vs 2.3 ± 2.5; P < .0001).

CONCLUSION

Because of allergy and/or antibiotic resistance, several first-line antibiotics are not available for many older women with RUTIs. In nearly a third of women, nitrofurantoin was the only viable alternative.

In vitro release of interferon-gamma from peripheral blood lymphocytes in cutaneous adverse drug reactions

BACKGROUND

Cutaneous drug reactions are common but diagnostically challenging due to phenotypic heterogeneity and simultaneous exposure to multiple drugs. These limitations prompted the development of diagnostic tests.

AIMS

To evaluate the performance of an in vitro assay measuring interferon-gamma release from patients' lymphocytes in the presence of causative drugs for the diagnosis of drug reactions.

METHODS

Mononuclear cells derived from patients were incubated with and without suspected drugs, and increment of interferon-gamma levels was measured by ELISA. We performed a telephonic survey to evaluate the effect of stopping the drugs incriminated by the assay on cutaneous manifestations.

RESULTS

We assessed 272 patients who used 1035 medications. When assessed against the questionnaire data collected at least 6 months after stopping the causative drug, sensitivity was found to be 83.61% and specificity 92.67%. Likelihood ratio for a positive test is 11.40 and for a negative test 0.18. Positive predictive value is 75.37% and negative predictive value is 95.47%. The test was found to perform significantly better in females and in older patients.

CONCLUSIONS

Interferon-gamma release test is a useful adjunct tool in the diagnosis of cutaneous drug reactions.

The role of surfaces in catheter-associated infections

In this critical review the biocidal efficacies of a variety of antimicrobial coatings currently in use for catheter surfaces are discussed to formulate the best strategy for decreasing the risk of catheter-associated infections. The development of new coatings containing antimicrobial chemicals and light-activated antimicrobial agents, and their applicability for use in catheters are summarised (132 references).

Phenytoin desensitization in a child with symptomatic localization-related epilepsy

We reported a child with refractory partial seizures successfully managed by clinical desensitization to phenytoin. The patient had ischemic brain lesions due to cardiopulmonary arrest at 39 weeks of corrected age. He had complex partial seizures refractory to several antiepileptic drugs since 4 years of age. At 8 years 1 month of age, phenytoin was first administered. Fever and maculopapular rashes appeared at 10 days after phenytoin initiation, and then the drug was discontinued. At 8 years 8 months of age, desensitization was attempted because of refractoriness of seizures to drugs other than phenytoin. Desensitization was started at 1mg daily, and then the dose was doubled every week. His seizures were controlled by 150mg/day of phenytoin in combination with primidone. No problems have been observed during desensitization.

Immunoglobulin E-mediated reactions to corticosteroids

Allergic reactions to steroids are rare, but are becoming more commonly recognized by clinicians. Although many reactions are thought to be IgE mediated, most are adverse drug reactions caused by nonallergic mechanisms, some related to additives in the steroid preparation being administered. Provocative challenge with the suspected offending agent, serologic tests for allergen-specific IgE, and skin testing are the most reliable methods for assessing hypersensitivity to steroids, although none is infallible. Therapeutic options for patients with documented steroid allergy include the use of alternative steroid preparations, desensitization, and, possibly, the use of monoclonal anti-IgE antibodies.

Treatment of amatoxin poisoning: 20-year retrospective analysis

BACKGROUND

Amatoxin poisoning is a medical emergency characterized by a long incubation time lag, gastrointestinal and hepatotoxic phases, coma, and death. This mushroom intoxication is ascribed to 35 amatoxin-containing species belonging to three genera: Amanita, Galerina, and Lepiota. The major amatoxins, the alpha-, beta-, and gamma-amanitins, are bicyclic octapeptide derivatives that damage the liver and kidney via irreversible binding to RNA polymerase II.

METHODS

The mycology and clinical syndrome of amatoxin poisoning are reviewed. Clinical data from 2108 hospitalized amatoxin poisoning exposures as reported in the medical literature from North America and Europe over the last 20 years were compiled. Preliminary medical care, supportive measures, specific treatments used singly or in combination, and liver transplantation were characterized. Specific treatments consisted of detoxication procedures (e.g., toxin removal from bile and urine, and extracorporeal purification) and administration of drugs. Chemotherapy included benzylpenicillin or other beta-lactam antibiotics, silymarin complex, thioctic acid, antioxidant drugs, hormones and steroids administered singly, or more usually, in combination. Supportive measures alone and 10 specific treatment regimens were analyzed relative to mortality.

RESULTS

Benzylpenicillin (Penicillin G) alone and in association was the mostfrequently utilized chemotherapy but showed little efficacy. No benefit was found for the use of thioctic acid or steroids. Chi-square statistical comparison of survivors and dead vs. treated individuals supported silybin, administered either as mono-chemotherapy or in drug combination and N-acetylcysteine as mono-chemotherapy as the most effective therapeutic modes. Future clinical research should focus on confirming the efficacy of silybin, N-acetylcysteine, and detoxication procedures.

Corticosteroid-induced hypersensitivity reactions

OBJECTIVE

To review and present data on the prevalence, clinical manifestations, diagnostic techniques, and management options in patients with hypersensitivity reactions to corticosteroid preparations.

DATA SOURCES

All English language articles pertaining to human subjects were reviewed using the Pubmed database from 1964 to June 2002. Indexing terms used were anaphylaxis OR allergic OR anaphylactoid OR hypersensitivity AND steroid OR corticosteroid. Further cross-references were obtained after reviewing articles from the aforementioned search.

STUDY SELECTION

A total of 11,493 articles were identified with the above search terms. Only those articles, including letters and editorials, describing systemic reactions to steroids were included in the review. Excluded from our review were articles dealing with contact dermatitis to topical steroid preparations. This resulted in a total of 80 articles which were reviewed.

RESULTS

Although rare, steroid-induced hypersensitivity reactions do occur. They range from minor rashes to the more serious cardiovascular collapse. The mechanisms of steroid-induced adverse events vary from patient to patient, some being classic immunoglobulin E-mediated whereas others are pseudoallergic in nature. Skin testing and provocative challenges offer two ways to diagnose such reactions. Treatment consists of substituting the steroid with an alternative preparation which can be tolerated by the patient.

CONCLUSIONS

Although little is known about the epidemiology of steroid-induced hypersensitivity, because most data are derived from case reports, it is clear that steroid-induced hypersensitivity is a heterogeneous entity, with no single uniform mechanism. A great deal of work still needs to be done so that the pathogenesis of such adverse events can be clearly determined and effective therapeutic interventions devised.

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.

Factors associated with preventability, predictability, and severity of adverse drug reactions

OBJECTIVE

To determine the rate of adverse drug reactions (ADRs) in hospitalized patients in an Iranian hospital and to assess factors associated with preventability, predictability, and severity of ADRs.

DESIGN AND PARTICIPANTS

A prospective, randomized study was conducted on 370 patients in a hospital at the Tehran Medical Sciences University, from March to December 1996. Patients who experienced at least one ADR (n = 62) were entered into the database. Preventability, predictability, and severity of reactions were determined, based on the available algorithms developed by other investigators.

SETTING

A 1200-bed tertiary care university teaching hospital in Tehran, Iran.

RESULTS

Approximately 16.8% (n = 62) of the 370 patients who were included in this study had at least one ADR. One hundred two ADRs were reported during this study. Approximately 58.8% of the ADRs (60 reactions) were identified as preventable reactions and 96.1% as predictable reactions. The severity of 9.8% of the ADRs was identified as mild, 86.3% as moderate, 1% as severe, and 2.9% as lethal. The length of hospitalization increased with the severity of the ADRs. Preventable ADRs were more severe than those that were nonpreventable. In addition, the incidence of preventable ADRs increased with the patients' age and caused longer hospitalization than did nonpreventable ones. The most predictable ADRs were hematologic.

CONCLUSIONS

This study noted that the rate of ADRs in Iran is probably as high as the rate in other parts of the world. These results indicate a need for a strong national ADR program that detects and reports adverse drug events in Iran.

Selective allergic reaction to oral cloxacillin

BACKGROUND

Previous observations indicate that in some instances subjects allergic to penicillins may experience an allergic reaction after taking the drug by one route but have good tolerance after being administered the same drug by a different route.

OBJECTIVE

The purpose was to establish if cloxacillin (CLX) induced a selective response only after oral route administration in a suspected case and to study if there were differences between the oral and parenteral formulations.

METHODS

Skin tests were carried out using benzylpenicillin (BP) conjugated to poly-L-lysine (BPO-PLL), minor determinant mixture of benzylpenicillin (MDM), ampicillin (AMP), amoxicillin (AX) and cloxacillin (CLX). Radioallergosorbent assay (RAST) was carried out using BPO-PLL, AX-PLL and CLX-PLL sensitized discs. In the case the skin tests and RAST were negative, a controlled challenge administering the drug by both oral and parenteral route was made. Urine samples were taken at prechallenge (basal levels) and at three periods after challenge (1-3, 3-6 and 6-9 h). Analysis of oral and parenteral formulations was made by HPLC chromatography.

RESULTS

All skin tests and RASTs were negative. With the challenge tests the patient tolerated parenteral BP and oral phenoxymethyl penicillin (PV) and oral and parenteral AMP up to therapeutic concentrations. Parenteral CLX (500 mg) was also tolerated but 30 min after administering 50 mg by the oral route progressive generalized erythema with pruritus, facial angioedema and tachycardia developed. Urine samples taken during the challenge tests showed an increased excretion of N-methyl histamine (N-MH) 3 h after challenge with oral CLX but no change in N-MH levels after challenge with parenteral CLX or the other penicillins, indicating that histamine was released during the allergic episode with oral CLX. HPLC analysis of the oral and parenteral CLX formulations indicated that there were no differences and that neither polymers no other contaminant materials were present.

CONCLUSION

Although the nature of the allergenic determinant involved in the induction of the reaction is not yet known, the oral route may have favoured the production of a metabolite not generated by the parenteral route.

Basic aspects related to penicillin-allergy skin testing: on the variability of the hapten-paratope interaction

Ampicillin and benzylpenicillin conjugated to human serum albumin were used as immunogens in order to obtain antihaptenic IgG responses in outbred guinea pigs according to different schedules, all involving complete Freund's adjuvant. The individual responses were characterized by ELISA and by ELISA inhibition using ampicillin, benzylpenicillin, and carbenicillin peptidic conjugates for coating and for inhibition. In several instances, drastically reduced cross-reactivity and even its absence were observed, although the penicillin antigens differ only in the side-chain. The notion that the invariantly present thiazolidine ring will always provide significant binding to antibodies against all penicillins differing only in the side-chain has to be dropped. The experiments were performed in relation to newer findings of clinical penicillin-allergy skin testing which suggest that benzylpenicillin-based reagents alone are not able to detect or predict all reactions against semisynthetic penicillins. The experimental evidence here obtained corroborates this conclusion.

Drug allergies in the surgical population

Many patients claim to have drug allergies. However, the signs and symptoms of "allergic reactions" are seldom documented and the drug allergies are rarely properly assessed. The goal of this study was to determine the incidence of claimed "drug allergies" in a surgical population. After obtaining institutional approval, the study was carried out at five hospitals affiliated with Dalhousie University. Patients were interviewed by the investigators during the preoperative anaesthetic evaluation over six months and all signs and symptoms of drug reactions were recorded. The validity of the claimed allergy was based on the history. The allergies were assigned to one of three groups: (1) High probability of an allergic reaction: one or more of the signs and symptoms typical of an immunological reaction, with or without a family history, or a history of atopy; (ii) Low probability of an allergic reaction: signs and symptoms of the reaction were predictable reactions or side effects of the drug, without the occurrence of reactions mentioned above; or (iii) Unknown status: no information concerning the reaction of history was available. Of 1818 adult and paediatric patients (914 female/904 male) interviewed, 511 (28.1%) claimed to have one or more drug allergies (a total of 671 allergies). More women than men claimed to have drug allergies (60.3% vs 39.7%) and there was a positive correlation between age, number of medications and reported drug allergies. Antibiotics (50%), opioids (27%), non-steroidal anti-inflammatory agents (10%), and sedatives (5%) accounted for 92% of all claimed drug allergies. Overall, 50% of claimed allergies had a high probability of true allergic reactions.(ABSTRACT TRUNCATED AT 250 WORDS)

Allergic reactions to betalactams: studies in a group of patients allergic to penicillin and evaluation of cross-reactivity with cephalosporin

A group of 34 penicillin-allergic patients was studied to determine skin test reactivity to the different penicillins involved in inducing the allergic reaction and the cross-reactivity with side-chain-related and side-chain-unrelated cephalosporins. All the subjects selected for the study had to be skin test positive to at least one of the following determinants: benzyl-penicilloyl-polylysine (BPO-PLL), minor-determinant mixture (MDM), amoxicillin (AX), or ampicillin (AMP), or to possess in vitro IgE to the following conjugates: benzyl-penicilloyl-human-serum albumin (BPO-HSA), ampicilloyl-human-serum albumin (AMP-HSA), and amoxicilloyl-human-serum albumin (AX-HSA). Cephalexin (CE) and ceftazidime (CEF) were used to assess cross-reactivity. If skin tests to any of these compounds were positive, the patient was considered to be allergic; if negative, a challenge test was performed. Sixteen patients (47%) were skin test positive to BPO and/or MDM, and nine (26%) exclusively to AX and/or AMP. In three cases (8%), the RAST was positive although the skin test was negative; one to BPO-HSA and two to AX-HSA and AMP-HSA. Six patients (17%) needed to be challenged with the penicillin involved to establish the diagnosis. In five patients (14%), the skin tests were positive to CE and in none to CEF. In all the others, the skin tests were negative to both cephalosporins, and the patients tolerated the drugs when challenged. These results indicate the relevance of side-chain-specific minor determinants in betalactams allergy and provide support for the role of this chemical structure in the evaluation of cross-reactivity between penicillins and cephalosporins.

Positivity of patch tests in cutaneous reaction to diclofenac. Two case reports

Immune-mediated reactions to NSAIDs are unusual. We have observed two cases of maculopapular eruptions occurring 48-72 h after administration of diclofenac sodium. Patch tests performed with diclofenac were positive. The histopathologic findings resembled those of contact dermatitis with different degrees of dermal involvement. Clinical, allergologic, and histopathologic patterns strongly suggest a type IV mechanism of hypersensitivity. Patch tests play an important role in the assessment of possible immunologic mechanisms underlying cutaneous reactions to drugs.

Lichenoid drug eruptions

Lichen planus-like or lichenoid eruptions from certain drugs and compounds can closely mimic idiopathic lichen planus. The patient's history and physical examination histopathologic criteria, and certain tests can assist in the differentiation between a lichenoid drug eruption and idiopathic lichen planus and in the identification of the offending drug.

Imbalance of CD45R and CDw29 helper cell subsets after seven days of culture from penicillin hypersensitive patients

Specific PBMC proliferation to penicillin represents one of the in vitro diagnostic procedures to show antigenic sensitization. Nine patients with suggestive clinical history of penicillin hypersensitivity, significant stimulation index in the lymphocyte transformation test (LTT), and increased CD25 expression were selected. Their phenotypic expression of T-cell subset markers was compared with that of six normal subjects after 7 days of culture. Higher percentages of CD45R and CDw29 positive cells were found in penicillin-hypersensitive patients. This group of patients showed a significantly (P less than 0.01) higher percentage of CD45R positive cells compared with normal subjects, after 7 days of culture. The percentage of CD45R cells did not differ between patients and normal subjects at day 0, and the progressive decrease of CD45R positive cells in culture of normal subjects was not observable in our patients. These results suggest that the patients with penicillin hypersensitivity have an imbalance of CD45R/CDw29 ratio after 7 days of culture, with a higher expression of CD45R positive cells.

Drug allergy. Best diagnostic and treatment approaches

The problems in identifying and managing drug allergy are myriad, primarily because of the number of possible agents involved, the lack of objective diagnostic methods, and the varied signs and symptoms that may occur. Allergic reactions can be life-threatening and are avoidable in most cases. A careful and serious approach is important because the effect of medical decisions can be significant. Physicians should keep in mind that an allergic reaction to any drug can occur in any patient at any time.

Drug allergy

Adverse reaction to drugs is a common problem in the pediatric population. This article discusses the different types of adverse drug reactions and their mechanisms. Also included are representative clinical syndromes of drug hypersensitivity reactions, as well as certain organ systems syndromes. Finally, diagnosis and management of allergic reactions to particular drugs such as penicillin, iodinated contrast dye, insulin, and others are discussed.

Allergic reactions during anesthesia

Any drug or blood product administered in the perioperative period has the potential to produce a life-threatening allergic (immune reaction) called anaphylaxis. Anaphylactic reactions represent adverse reactions mediated by immunospecific antibodies (IgE and IgG) that interact with mast cells, basophils, or the complement system to liberate vasoactive mediators and recruit other inflammatory cells. Activation of humoral and cellular pathways produces characteristic responses in the respiratory (bronchospasm and upper airway edema), cardiovascular (vasodilation and increased capillary permeability), and cutaneous systems (wheal and flare). Other predictable adverse drug reactions may mimic anaphylaxis to produce similar physiologic consequences independent of allergy (immune responses). Rapid and timely cardiopulmonary intervention with airway maintenance, epinephrine, and volume expansion is essential to avoid an adverse outcome. Severe reactions may be protracted, especially during anesthesia, requiring even larger doses of catecholamines and intensive care observation.

Analgesics, allergy and asthma

Intolerance to analgesics is common in patients with bronchial asthma, nasal polyps and urticaria. Symptoms of intolerance resemble those of allergy, but the events precipitating them can rarely be traced to reactions between the drug and a specific antibody or sensitised T-lymphocytes. In 8 to 20% of adult asthmatics, aspirin and several other analgesics provoke asthmatic attacks, probably through inhibition of cyclo-oxygenase. This is a distinct and important clinical syndrome with a specific history, course and clinical presentation and a number of unique peculiarities which still require elucidation at the biochemical level. Up to 40% of patients with chronic urticaria develop an obvious increase in weals and swelling after taking aspirin. These reactions occur only when urticaria is active, and though the reason for them is not known, it appears that different mechanisms may be responsible in different patients. Skin reactions other than exacerbation of chronic urticaria are less common, but may create serious clinical problems. The clinical background of a patient often determines the type of adverse response to an analgesic. Thus, in certain individuals, analgesics can produce anaphylactic reactions and/or urticaria, probably through an immunological mechanism, while in some asthmatics they precipitate bronchoconstriction, probably through inhibition of bronchial cyclooxygenase. Study of untoward reactions to analgesics not only leads to safer pharmacotherapy, but it also offers a fascinating model for better understanding of some diseases.