Immediate reactions

Although immediate reactions of anaphylaxis, bronchospasm, and urticaria have been reported, most commonly patients exhibiting an adverse reaction develop a maculopapular rash, usually after several days of therapy. They may also develop fever and eosinophilia (80,219). Cefoperazone (34) and ceftriaxone (39), having greater biUary excretion than other cephalosporins, are associated with an increased risk of diarrhea, which may be caused by selection of cytotoxin producing stains of Clostridium difficile (219). 

Hydrated metal sulphates have long been used to study water removal processes, and characteristic kinetic behaviour is conveniently illustrated by reference to these substances. Frost and co-workers [602,603] have investigated the structures, stabilities and adsorption properties of various intermediate amorphous phases, the immediate reaction products which can later undergo reorganization to yield crystalline phase. 

In the usual high-vacuum apparatus I placed aluminum borohydride onto a sample of uranium tetrafluoride. I observed an immediate reaction, with formation of green crystals which could be moved about the vacuum apparatus. As it happened, on the very day I was performing the synthesis, we had a visit from Professor H. C. Urey, who was in charge of the overall study. He immediately asked us to increase our research effort and undertake to prepare uranium tetraborohydride on a relatively large scale, adequate for testing. 

Laroche D. Aimone-Gastin 1. Dubois F, Huet H. Gerard P. Vergnaud MC, Mouton-Faivre C, Gueant JL. Laxenaire MC. Bricard H Mechanisms of severe, immediate reactions to iodinated contrast material. Radiology 1998 209 183. 

The p-lactams (penicillins and their derivatives) are the drugs which most frequently cause IgE-mediated anaphylactic reactions. Diagnosis is based on skin tests. To date, the best vaUdated in vitro diagnostic methods are specific IgE and BAT. As for the determination of specific IgE using ImmimoCap (Phadia AB, Uppsala, Sweden), the sensitivity of the technique in the diagnosis of immediate reaction to (3-lactams with positive skin test ranges, according to the study, from 37 to 54% with a specificity of between 83 and 100% [23,24]. 

Radiocontrast media (RCM) are highly concentrated solutions of triiodinated benzene derivatives used for performing diagnosis and treatment of vascular disease and enhancement of radiographic contrast [1,2]. However, adverse reactions after RCM administration are common [3]. The frequency and mechanisms of hypersensitivity reactions differ between monomeric and dimeric as well as between ionic and non-ionic types of RCM. Mild immediate reactions have been reported to occur in 3.8-12.7% of patients receiving ionic monomeric RCM and in 0.7-3.1% of patients receiving non-ionic RCM [4-6]. Severe immediate adverse reactions to ionic RCM have been reported in 0.1-0.4% of intravenous procedures, while reactions to nonionic iodinated RCM are less frequent (0.02-0.04%) [4-7]. Fatal hypersensitivity... 

During the past decade, a lot of data on the pathogenesis of non-immediate reactions induced by RCM has indicated that the majority of these reactions are T-cell-mediated reactions (table 2) ... 

Numerous positive delayed skin tests in patients with contrast medium-induced non-immediate skin reactions have been reported when the patients were tested with the culprit contrast medium [summarized in 1]. In a large European multicenter study, 37% of patients with non-immediate reactions were positive in delayed IDEs and/or patch tests [13]. The majority of the patients also reacted to the culprit contrast medium and also to other, structurally similar RCM. Notably, in more than 30% of those skin test-positive patients a RCM had been administered for the first time. Thus, there is a lack of a sensitization phase. Again it may be hypothesized that these previously non-exposed patients may have already been sensitized. Different patterns of RCM cross-reactivity indicate that several chemical entities could be involved. No positive skin tests have been obtained with other contrast medium excipients, such as ethylenediaminetetraacetic acid (EDTA), and only rarely patients have been found to react to inorganic iodide. 

Arnold AW, Hausermann P, Bach S, Bircher AJ Recurrent flexural exanthema (SDRIFE or baboon syndrome) after administration of two different iodinated radiocontrast media. Dermatology 2007 214 89-93. Laroche D Immediate reactions to contrast media mediator release and value of diagnostic testing. Toxicology 2005 209 193-194. 

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