Outcomes of premedication for non-ionic radio-contrast media hypersensitivity reactions in Korea

Pharmacological Prevention of Hypersensitivity Reactions Caused by Iodinated Contrast Media: A Systematic Review and Meta-Analysis

Objectives: Hypersensitivity reactions (HSRs) are uncommon but serious adverse events following the administration of iodinated contrast media (ICM) prior to CT imaging. While premedication is almost universally given in high-risk patients, there is a lack of evidence regarding the efficacy of such premedication. This study aims to determine the efficacy of premedication with corticosteroids prior to ICM administration in the prevention of HSRs through meta-analysis. Materials and Methods: An extensive review of the literature yielded 404 potentially relevant studies. Of these, five studies met the inclusion criteria of this meta-analysis. Pooled HSR event rates were obtained from each of the studies for both patients who had and who had not received premedication with corticosteroids. Heterogeneity between studies was also determined. Results: A total of 736 patients across all five studies were included in the analysis. Patients who did not receive premedication had initial pooled HSR rates of 0.16 (95% CI, 0.07−0.35) across all studies. Following premedication, pooled HSR rates dropped to 0.02 (95% CI, 0.01−0.06). Patients who had prior HSRs were significantly less likely to experience HSRs (OR = 0.09; 95% CI, 0.03−0.25; p < 0.00001) after treatment with premedication. Conclusions: This meta-analysis offers evidence for the reduction in the recurrence of moderate and severe HSRs in patients who have a history of such reactions. Premedication with corticosteroids prior to ICM administration is thus highly recommended in high-risk patients.

Clinical impact of allergy and pre-medication in CT studies with low-osmolality intravenous iodinated contrast media

AIM

To evaluate the occurrence and severity of allergic reactions to iodinated contrast media (ICM), including associated risk factors and the impact of pre-medication.

MATERIALS AND METHODS

Data on patients who had experienced allergic reactions during outpatient computed tomography (CT) examinations between January 2014 and September 2018 were analysed retrospectively. Response severity was assessed according to validated criteria. A control group was selected among individuals who underwent CT during the study period and did not experience allergic reactions.

RESULTS

Screening of 36,920 CT studies revealed 74 (0.2%) individuals with systemic reactions to ICM. No significant differences in patient characteristics were found among patients who experienced mild (n=54), moderate (n=17), or severe (n=4) reactions. Previous ICM allergy was reported in 10 patients (13.3%). Patients with a history of ICM allergy had mild (9/10) or moderate (1/10) reactions, with one individual showing decreased intensity of the allergic response compared to a previous event. Within the control group, four patients (4%) had previous ICM allergy. In these individuals, lack of allergic reactions could not be attributed to pre-medication. All patients with severe reactions did not have a prior history of ICM allergy.

CONCLUSION

Severe allergic reactions to ICM are rare, lack significant risk factors, and do not appear to be impacted by pre-medication. The findings presented herein highlight the need for prospective work that will re-evaluate the yield of pre-medication protocols.

Outcomes in patients with known contrast allergy undergoing contrast-enhanced endourological procedures: a retrospective cohort study

BACKGROUND

Intravenous administration of iodinated contrast agents carries the risk of allergic reaction, yet this risk is unclear with administration into the urinary tract. We sought to evaluate patients with known contrast, iodine, or shellfish allergies for allergic response when undergoing urologic imaging requiring intraluminal, urinary tract contrast administration.

MATERIALS AND METHODS

We retrospectively reviewed consecutive patients undergoing endourologic procedures from 2010 to 2015 at our institution. Clinical records were reviewed for demographics, medical history, allergies, procedure details, fluids administered, anesthetic and pharmacologic agents administered, and continuous monitoring parameters. Patients with known allergies to iodine, shellfish, and/or contrast were identified and evaluated for clinical or hemodynamic signs of allergy. A convenience sample of 50 patients without allergy history was used as a comparison group.

RESULTS

We identified 1,405 procedures involving 1,000 consecutive patients. Procedures included retrograde pyelograms and antegrade nephrostograms. Eighty-six cases involving 58 patients with contrast, iodine, or shellfish allergies were identified. Of those with contrast allergy history, 18 (20.1%) cases involved patients with a history of anaphylactic reaction. Of these, 11 (61%) received steroid prophylaxis. No patients in either group (Allergy, No Allergy) were identified as having an allergic reaction during the procedure. There were no statistically significant differences in intraoperative intravenous fluids (p=0.931), procedure duration (p=0.747), or vasopressor use (p=0.973) between groups. Due to the zero event rate of contrast allergy, we used the Hanley and Lippman-Hand method, which places true population risk (95% confidence interval) of a significant event at less than 3.5%.

CONCLUSIONS

In 86 cases involving patients with a history of contrast allergy, we found no evidence of clinically significant allergic reaction to intraluminal endourologic contrast administration under continuous anesthesia monitoring. The risk of significant reactions to contrast administered within the urinary tract appears to be low in these patients, regardless of prophylaxis.

Premedication for Iodinated Contrast Media Induced Immediate Hypersensitivity Reactions

Purpose of the review

Premedication using antihistamines and/or corticosteroids has been widely used to prevent reoccurrence of immediate hypersensitivity reactions (iHR) after iodinated contrast media (ICM). However, efficacy has been debated, especially in high-risk patients. Novel findings on the role and risks of premedication and preventive strategies are summarized.

Recent findings

The rate and severity of iHR occurring despite premedication indicate that premedication is not a panacea and the intensity usually reflects that of the initial reaction. Next, the number needed to treat (NNT) to prevent one serious ICM-mediated event using corticosteroid-based premedication is high and associated with a diagnostic delay. Randomly changing the ICM has been suggested as an additional preventive measure, whilst others used a skin test–based approach to identify a subgroup of ICM allergic patients and negative skin test–based alternatives with a high negative predictive value.

Summary

Growing evidence indicates the need to discriminate between non-allergic iHR that are most likely non-obligatory and susceptible to premedication, and rare type I allergic iHR that can be identified using skin testing, especially in those with a severe iHR. Although premedication reduces reoccurrence of mild iHR, it is not always efficacious and should be balanced against side effects, a high NNT and an uncertain efficacy physicians should not blindly rely on. Future work should evaluate combined approaches of an allergy-driven ICM selection and endotype-driven premedication regimens in patients with non-allergic iHR.

Intradermal Testing With Radiocontrast Media to Prevent Recurrent Adverse Reactions

OBJECTIVE. Adverse drug reactions (ADRs) to radiocontrast media are a significant social and economic burden and are difficult to predict. Because some ADRs to radiocontrast media may be immunologically induced, a skin test with diluted 1:10 radiocontrast media has been used to predict ADRs. However, using this test in clinical practice is difficult because of its low sensitivity. SUBJECTS AND METHODS. This study enrolled 36 patients with a history of immediate ADR to radiocontrast media who visited the Allergy and Asthma Clinic of Severance Hospital from 2017 to 2018. Patients underwent intradermal testing (IDT) with five types of diluted (1:10) and undiluted radiocontrast media (iohexol, iobitridol, iopamidol, iopromide, and iodixanol). The IDT result was regarded as positive if at least one radiocontrast medium elicited a positive reaction. Positivity of IDT and sensitivity to the culprit radiocontrast medium were calculated and compared. For subsequent CT examinations with a radiocontrast medium, the contrast agent eliciting a negative skin reaction in IDT was selected, excluding the previous culprit radiocontrast medium. RESULTS. IDT positivity and sensitivity for the culprit radiocontrast medium at 1:10 dilution were 47.2% and 47.2%, respectively, whereas the positivity and sensitivity for the undiluted radiocontrast medium were 86.1% and 75.0%, respectively. The positivity and sensitivity were higher with frequent radiocontrast medium use or with severe reaction. Of 22 patients who underwent another CT examination with the contrast medium selected on the basis of IDT results, 21 (95.5%) did not experience an ADR. CONCLUSION. IDT to prevent ADR should be performed with undiluted radiocontrast medium. Selecting an alternative radiocontrast agent on the basis of IDT results can be clinically useful to prevent recurrent ADRs to radiocontrast media.

Evidence- and consensus-based recommendations for the use of pegvaliase in adults with phenylketonuria

Purpose

Phenylketonuria (PKU) is a rare metabolic disorder that requires life-long management to reduce phenylalanine (Phe) concentrations within the recommended range. The availability of pegvaliase (PALYNZIQ™, an enzyme that can metabolize Phe) as a new therapy necessitates the provision of guidance for its use.

Methods

A Steering Committee comprising 17 health-care professionals with experience in using pegvaliase through the clinical development program drafted guidance statements during a series of face-to-face meetings. A modified Delphi methodology was used to demonstrate consensus among a wider group of health-care professionals with experience in using pegvaliase.

Results

Guidance statements were developed for four categories: (1) treatment goals and considerations prior to initiating therapy, (2) dosing considerations, (3) considerations for dietary management, and (4) best approaches to optimize medical management. A total of 34 guidance statements were included in the modified Delphi voting and consensus was reached on all after two rounds of voting.

Conclusion

Here we describe evidence- and consensus-based recommendations for the use of pegvaliase in adults with PKU. The manuscript was evaluated against the Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument and is intended for use by health-care professionals who will prescribe pegvaliase and those who will treat patients receiving pegvaliase.

Radiographic and magnetic resonances contrast agents: Essentials and tips for safe practices

With extended and continued expansion of medical imaging utilization in modern medical practice over last decade, radiologists as well as other faculty staff dealing with radiographic and magnetic resonances contrast media (CM) have to be well oriented with their potential hypersensitivity reactions and recognize high-risk groups liable to develop it and enable early recognition. Radiologists and other medical staff involved in administration and dealing with CM have to be ready to implement prompt, practical and effective management plan to deal with these scenarios should they emerge. Strategies to prevent potential contrast-induced acute and delayed renal injuries have to be routinely exercised. Paying attention to the pregnant and nursing women, pediatrics, diabetics, as well as other fragile populations is of utmost importance for patient safety during contrast administrations. Radiologists should play a pivotal role in orienting patients about necessity to use CM for their imaging studies, in case it is needed, and assure them about its safety. Moreover, they have to be oriented with the medico-legal issues related to use of CM. These will pay as improved patient safety as well as safe daily working environmentat different levels of radiology practices.

Outcomes of corticosteroid prophylaxis for hypersensitivity reactions to low osmolar contrast media in high-risk patients

BACKGROUND

Corticosteroid prophylaxis has been widely adopted for the prevention of acute allergic-like reactions to iodinated contrast media, but its use is still controversial because there is no strong evidence supporting its efficacy before administration of nonionic low osmolar contrast media (LOCM).

OBJECTIVE

To assess the outcomes of premedication in patients with previous acute allergic-like reactions to LOCM in clinical practice.

METHODS

A retrospective study was performed on 322 high-risk patients who were reexposed to LOCM after premedication composed of antihistamines and/or systemic corticosteroids because of a previous history of acute allergic-like reactions to LOCM.

RESULTS

After premedication, 275 patients (85.4%) did not experience any reaction, but 47 patients (14.6%) still experienced a breakthrough reaction. The premedication rate and amount of corticosteroid administered were significantly higher in the nonrecurrence group than in the recurrence group (P = .04 and P = .04, respectively), and a linear trend was observed in the use of corticosteroid premedication and the efficacy of prevention (P for trend = .02). Multivariate binary logistic regression revealed that corticosteroid premedication was effective in preventing recurrence (odds ratio, 0.284; 95% confidence interval, 0.103-0.784). Nonetheless, despite corticosteroid premedication, 3.4% of high-risk patients still experienced moderate to severe reactions, and 14.3% of patients with a severe index reaction again had a severe reaction.

CONCLUSION

Premedication with corticosteroids seems to be helpful in reducing the overall rate of recurrence of acute allergic-like reactions to LOCM in high-risk patients, but patients with severe index reactions are still at risk of developing severe reactions despite corticosteroid premedication.

Preventing Allergic Reactions to Gadolinium-Based Contrast Agents

Although the low incidence of immediate-type gadolinium-based contrast agent (GBCA) allergic reactions is widely known, preventing these reactions and properly managing them to reduce their adverse sequel can improve the already exceedingly favorable GBCA safety profile. This review article should help those who order, supervise, or administer GBCA contrast agents, including recognizing and handling allergic reaction risks intrinsic to their use. Areas of focus include factors indicating increased allergic reaction risk, patient selection strategies, skin testing, premedication, and treatment of adverse events.

The efficacy of single premedication with antihistamines for radiocontrast media hypersensitivity

Background

Single premedication with antihistamines for radiocontrast media (RCM) hypersensitivity is frequently used in real world at the emergent situation although its efficacy is not proven.

Objective

To evaluate the effect of intravenous antihistamines as a premedication in general population who had experience of mild adverse reactions to iodinated RCM.

Methods

A retrospective observational study on 14,785 subjects who had RCM-enhanced computed tomography scans between January 2014 and December 2015 in Seoul National University Hospital Gangnam Healthcare Center, Seoul, South Korea.

Results

Among 453 subjects who had a history of mild RCM-induced hypersensitivity reactions, 273 subjects had a single premedication of intravenous antihistamine. When comparing antihistamine-premedication group and nonpremedication group, there is no protective effect of antihistamines on the incidence rate and severity of hypersensitivity (10.6% vs. 11.7%, p = 0.729).

Conclusion

The clinical efficacy of a single premedication of antihistamines for mild RCM-induced hypersensitivity was not confirmed.

Should patients with risk factors be tested for hypersensitivity to contrast media: a prospective study

BACKGROUND

Previous hypersensitivity reactions to contrast media (CM), atopy, atopic disease, drug allergy, and age (20-29 or >55) are risk factors for CM hypersensitivity reactions. Our aim was to evaluate whether these risk factors should prompt skin testing for diagnosing CM allergy.

METHODS

The study was conducted among patients referred for allergy testing with CM. Skin tests were performed with non ionic or gadolinium CM, recommended by a radiologist. After completion of tests patients were telephonically queried on their symptoms of reactions.

RESULTS

151 risk patients (53 men, 98 women; mean age 55.2) were included in the study. Only 13 (9 %) had a history of hypersensitivity reaction to CM. Compared with the other patients, atopy was significantly more common in patients with a history of CM hypersensitivity reactions. Female gender and mean age were also higher, but not significant. All of the tests with CMs were negative. Only one patient reported urticaria within 1-2 min after administration of CM (telephonically).

CONCLUSIONS

Atopy can increase the risk of CM allergy. However, skin tests with CMs may be inefficient, unnecessary, and time-consuming, except in cases with a history of CM allergy. Premedication protocols appear to be beneficial in patients with a history of CM allergy and cannot be recommended for patients with well-controlled asthma, rhinitis, atopic dermatitis or history of drug allergy.

Skin tests in patients with hypersensitivity reaction to iodinated contrast media: a meta-analysis

BACKGROUND

Patients with a previous history of hypersensitivity reaction (HSR) to iodinated contrast media (ICM) are at high risk of the development of HSR to ICM. Many studies have tried to evaluate the diagnostic potential of skin tests in this population but have not yet reached a common conclusion. We investigated the role of skin tests in patients with HSR to ICM in terms of positive rate, cross-reactivity rate, and tolerability to skin test-negative ICM according to the type of HSR.

METHODS

We performed literature searches of the MEDLINE and EMBASE databases and included studies where skin tests were performed in patients with HSR to ICM, with extractable outcomes. Outcomes were pooled using a random-effects model.

RESULTS

Twenty-one studies were included. Pooled per-patient positive rates of skin tests were 17% (95% CI, 10-26%) in patients with immediate HSR, and up to 52% (95% CI, 31-72%) when confined to severe immediate HSR. Among patients with nonimmediate HSR, the positive rate was 26% (95% CI, 15-41%). The pooled per-patient cross-reactivity rate was higher in nonimmediate HSR (68%; 95% CI, 48-83%) than that in immediate HSR (39%; 95% CI, 29-50%). Median per-test cross-reactivity rates between pairs of ICM were 7% (IQR, 6-9%) in immediate HSR and 38% (IQR, 22-51%) in nonimmediate HSR. Pooled per-patient recurrence rates of HSR to skin test-negative ICM were 7% (95% CI, 4-14%) in immediate HSR and 35% (95% CI, 19-55%) in nonimmediate HSR.

CONCLUSION

Skin tests may be helpful in diagnosing and managing patients with HSR to ICM, especially in patients with severe immediate HSR.

The potential utility of iodinated contrast media (ICM) skin testing in patients with ICM hypersensitivity

Both immediate and delayed hypersensitivity reactions to iodinated contrast media (ICM) are relatively common. However, there are few data to determine the clinical utility of immunologic evaluation of ICM. To evaluate the utility of ICM skin testing in patients with ICM hypersensitivity, 23 patients (17 immediate and 6 delayed reactions) were enrolled from 3 university hospitals in Korea. With 6 commonly used ICM including iopromide, iohexol, ioversol, iomeprol, iopamidol and iodixanol, skin prick (SPT), intradermal (IDT) and patch tests were performed. Of 10 patients with anaphylaxis, 3 (30.0%) and 6 (60.0%) were positive respectively on SPTs and IDTs with the culprit ICM. Three of 6 patients with urticaria showed positive IDTs. In total, 11 (64.7%) had positive on either SPT or IDT. Three of 6 patients with delayed rashes had positive response to patch test and/or delayed IDT. Among 5 patients (3 anaphylaxis, 1 urticaria and 1 delayed rash) taken subsequent radiological examinations, 3 patients administered safe alternatives according to the results of skin testing had no adverse reaction. However, anaphylaxis developed in the other 2 patients administered the culprit ICM again. With 64.7% (11/17) and 50% (3/6) of the sensitivities of corresponding allergic skin tests with culprit ICM for immediate and delayed hypersensitivity reactions, the present study suggests that skin tests is useful for the diagnosis of ICM hypersensitivity and for selecting safe ICM and preventing a recurrence of anaphylaxis caused by the same ICM.

Contrast-free diagnosis and treatment of coronary artery disease guided by integrated cardiac imaging: concept and first clinical experience

The use of iodinated contrast media (ICM) remains a potential hazard for patients undergoing diagnostic cardiac imaging and percutaneous coronary intervention. In particular patients with history of prior adverse reaction to a contrast agent are at a high risk in case of re-exposure, even if designated premedication is administered. Based on a patient with recurrent angina pectoris and history of systemic anaphylactic reaction to ICM, we describe the logical stepwise approach from diagnostic imaging to safe and successful imaging guided percutaneous coronary intervention without the use of contrast agent.

Breakthrough reactions of iodinated and gadolinium contrast media after oral steroid premedication protocol

BACKGROUND

Adverse reactions to iodinated and gadolinium contrast media are an important clinical issue. Although some guidelines have proposed oral steroid premedication protocols to prevent adverse reactions, some patients may have reactions to contrast media in spite of premedication (breakthrough reaction; BTR).The purpose of this study was to assess the frequency, type and severity of BTR when following an oral steroid premedication protocol.

METHODS

All iodinated and gadolinium contrast-enhanced radiologic examinations between August 2011 and February 2013 for which the premedication protocol was applied in our institution were assessed for BTRs.

RESULTS

The protocol was applied to a total of 252 examinations (153 patients, ages 15-87 years; 63 males, 90 females). Of these, 152 were for prior acute adverse reactions to contrast media, 85 were for a history of bronchial asthma, and 15 were for other reasons. There were 198 contrast enhanced CTs and 54 contrast enhanced MRIs. There were nine BTR (4.5%) for iodinated contrast media, and only one BTR (1.9%) for gadolinium contrast media: eight were mild and one was moderate. No patient who had a mild index reaction (IR) had a severe BTR.

CONCLUSION

Incidence of BTRs when following the premedication protocol was low. This study by no means proves the efficacy of premedication, but provides some support for following a premedication protocol to improve safety of contrast-enhanced examinations when prior adverse reactions are mild, or when there is a history of asthma.

International consensus on (ICON) anaphylaxis

ICON: Anaphylaxis provides a unique perspective on the principal evidence-based anaphylaxis guidelines developed and published independently from 2010 through 2014 by four allergy/immunology organizations. These guidelines concur with regard to the clinical features that indicate a likely diagnosis of anaphylaxis -- a life-threatening generalized or systemic allergic or hypersensitivity reaction. They also concur about prompt initial treatment with intramuscular injection of epinephrine (adrenaline) in the mid-outer thigh, positioning the patient supine (semi-reclining if dyspneic or vomiting), calling for help, and when indicated, providing supplemental oxygen, intravenous fluid resuscitation and cardiopulmonary resuscitation, along with concomitant monitoring of vital signs and oxygenation. Additionally, they concur that H1-antihistamines, H2-antihistamines, and glucocorticoids are not initial medications of choice. For self-management of patients at risk of anaphylaxis in community settings, they recommend carrying epinephrine auto-injectors and personalized emergency action plans, as well as follow-up with a physician (ideally an allergy/immunology specialist) to help prevent anaphylaxis recurrences. ICON: Anaphylaxis describes unmet needs in anaphylaxis, noting that although epinephrine in 1 mg/mL ampules is available worldwide, other essentials, including supplemental oxygen, intravenous fluid resuscitation, and epinephrine auto-injectors are not universally available. ICON: Anaphylaxis proposes a comprehensive international research agenda that calls for additional prospective studies of anaphylaxis epidemiology, patient risk factors and co-factors, triggers, clinical criteria for diagnosis, randomized controlled trials of therapeutic interventions, and measures to prevent anaphylaxis recurrences. It also calls for facilitation of global collaborations in anaphylaxis research. IN ADDITION TO CONFIRMING THE ALIGNMENT OF MAJOR ANAPHYLAXIS GUIDELINES, ICON: Anaphylaxis adds value by including summary tables and citing 130 key references. It is published as an information resource about anaphylaxis for worldwide use by healthcare professionals, academics, policy-makers, patients, caregivers, and the public.

Radiocontrast media hypersensitivity in the Asia Pacific region

Radiocontrast media (RCM) is a major cause of drug hypersensitivity reactions as the medical application of RCM is increasing recently. RCM induced hypersensitivity reactions are considered as unpredictable type B reactions. Underlying mechanism of RCM induced hypersensitivity was previously regarded as nonimmunological mechanisms but recent studies suggest that immunological mechanisms could also be involved. As a result, the roles of skin tests and premedication are revisiting. As there has been no report that comprehensively summarized and analyzed the results of the studies on RCM hypersensitivity in the Asia Pacific region, we aimed to review the literatures on hypersensitivity reactions to RCM in terms of prevalence clinical manifestations, diagnostic approach, and preventive measures in the Asia Pacific region.

Anaphylaxis caused by intravenous fluorescein: clinical characteristics and review of literature

Anaphylaxis is a severe, potentially fatal, systemic allergic reaction that suddenly occurs after contact with an allergy-causing substance. The aims of this study were to evaluate the clinical characteristics and outcomes of patients who were diagnosed with anaphylaxis to fluorescein. The medical records of patients with anaphylaxis to intravenous fluorescein angiography (IVFA) admitted to the emergency department between January 2010 and June 2012 were retrospectively reviewed. Among 12,005 times of IVFA, a total of 10 patients (0.083 %) were included in this study. The mean age was 58.3 years, and 50.0 % were men. The most common presentation was hypotension (systolic blood pressure <90 mmHg) (70 %) followed by nausea and vomiting (60 %). Especially, patients with diabetes were more prone to develop hypotension and most hypotensive events occurred in less than 3 min. All of our patients recovered without sequelae and mortality following prompt and proper intervention. Although the incidence is low, anaphylaxis due to intravenous fluorescein can occur during IVFA. Physicians should be aware of this possible complication, and be prepared to treat it.

Synthesis and dual histamine H₁ and H₂ receptor antagonist activity of cyanoguanidine derivatives

Premedication with a combination of histamine H₁ receptor (H₁R) and H₂ receptor (H₂R) antagonists has been suggested as a prophylactic principle, for instance, in anaesthesia and surgery. Aiming at pharmacological hybrids combining H₁R and H₂R antagonistic activity, a series of cyanoguanidines 14-35 was synthesized by linking mepyramine-type H₁R antagonist substructures with roxatidine-, tiotidine-, or ranitidine-type H₂R antagonist moieties. N-desmethylmepyramine was connected via a poly-methylene spacer to a cyanoguanidine group as the "urea equivalent" of the H₂R antagonist moiety. The title compounds were screened for histamine antagonistic activity at the isolated ileum (H₁R) and the isolated spontaneously beating right atrium (H₂R) of the guinea pig. The results indicate that, depending on the nature of the H₂R antagonist partial structure, the highest H₁R antagonist potency resided in roxatidine-type compounds with spacers of six methylene groups in length (compound 21), and tiotidine-type compounds irrespective of the alkyl chain length (compounds 28, 32, 33), N-cyano-N'-[2-[[(2-guanidino-4-thiazolyl)methyl]thio]ethyl]-N″-[2-[N-[2-[N-(4-methoxybenzyl)-N-(pyridyl)-amino] ethyl]-N-methylamino]ethyl] guanidine (25, pKB values: 8.05 (H₁R, ileum) and 7.73 (H₂R, atrium) and the homologue with the mepyramine moiety connected by a six-membered chain to the tiotidine-like partial structure (compound 32, pKB values: 8.61 (H₁R) and 6.61 (H₂R) were among the most potent hybrid compounds. With respect to the development of a potential pharmacotherapeutic agent, structural optimization seems possible through selection of other H₁R and H₂R pharmacophoric moieties with mutually affinity-enhancing properties.

The Effectiveness of Automatic Recommending System for Premedication in Reducing Recurrent Radiocontrast Media Hypersensitivity Reactions

BACKGROUND

Non-ionic radiocontrast media (RCM) is rarely associated with hypersensitivity reactions. Premedication of patients who reacted previously to RCM with systemic corticosteroids and/or antihistamines can help reduce recurrent hypersensitivity reactions. However, premedication is still not prescribed in many cases for various reasons. This study aimed to determine the effectiveness of our novel RCM hypersensitivity surveillance and automatic recommending system for premedication.

METHODS AND RESULTS

Hospitalized patients with a history of RCM hypersensitivity were identified in an electronic medical record system that included a mandatory reporting system for past adverse drug reactions. In 2009, a novel automatic prescription system was added that classified index RCM reactions by severity and dispensed appropriate corticosteroid and/or antihistamine pretreatment prior to new RCM exposures. The data from 12 months under the previous system and 12 months under the current system were compared. The two systems had similar overall premedication rates (91% and 95%) but the current system was associated with a significantly higher corticosteroid premedication rate (65% vs. 14%), which significantly reduced the breakthrough reaction rate (6.7% vs. 15.2%). The current system was also associated with increased corticosteroid and antihistamine premedication of patients with a mild index reaction (61% vs. 7%) and a reduction in their breakthrough reaction rate (6% vs. 15%).

CONCLUSIONS

Premedication with corticosteroid and/or antihistamine, which was increased by our novel automatic prescription system, significantly reduced breakthrough reactions in patients with a history of RCM hypersensitivity.

Surveillance of contrast-media-induced hypersensitivity reactions using signals from an electronic medical recording system

BACKGROUND

Contrast-media (CM) hypersensitivity is a well-known adverse drug reaction. Surveillance of adverse drug reactions usually depends on spontaneous reports. However, the rate of spontaneous reports is low. Recent progress in information technology enables the electronic search on signals of adverse drug reactions from electronic medical recording (EMR) systems.

OBJECTIVES

To analyze the incidence and clinical characteristics of CM hypersensitivity using an EMR-based surveillance system.

METHODS

The surveillance system used signals from standardized terms within the international classification of nursing practice terms that can indicate symptoms of CM hypersensitivity and from the order codes for procedures that used contrast media, antihistamine, and epinephrine. The search strategy was validated by allergists comparing the electronic search strategy versus manually reviewing medical charts over one month. The main study covered for one year period.

RESULTS

Detection rate of the electronic search method was 0.9% (7/759), while that of the manual search method was 0.8% (6/759). EMR-based electronic search method was highly efficient: reduced the charts that needed to be reviewed by 96% (28/759). The sensitivity of electronic screening was 66.7%, specificity was 99.6%, and the negative predictive value was 99.7%. CM hypersensitivity reactions were noted in 266 among 12,483 cases (2.1%). Urticaria was the most frequent symptom (74.4%). CT was the most frequent procedure (3.6%) that induced CM hypersensitivity.

CONCLUSION

A surveillance system using EMR may be a useful tool in the study of drug hypersensitivity epidemiology and may be used in an adverse drug reaction alarm system and as a clinical, decision making support system.