Risk of Hypersensitivity Reactions to Iopromide in Children and Elderly: An Analysis of 132,850 Patients From 4 Observational Studies and Pharmacovigilance Covering >288 Million Administrations

PURPOSE

The aim of this study was to analyze the risk of hypersensitivity reactions (HSRs) to iopromide in children and elderly patients in comparison to adults.

MATERIALS AND METHODS

Four observational studies were pooled and analyzed (analysis I). In addition, spontaneous reports from 1985 to 2020 from the pharmacovigilance database were evaluated (analysis II). All patients received iopromide for angiographic procedures or contrast-enhanced computed tomography in various indications. In analysis I, a nested case-control analysis, including a multivariable logistic regression model, based on pooled observational study data, was performed. Cases were defined as patients with a typical and unequivocal HSR; controls were patients without any recorded reaction. In analysis II, all spontaneous reports on HSRs after iopromide administration recorded in the pharmacovigilance database were descriptively analyzed. Exposure estimates on the size of the exposed age groups were derived from sales data and data from market research. The primary target variable was the risk of HSR to iopromide in children (<18 years) and elderly patients (≥65 years) compared with adults (≥18 to <65 years).

RESULTS

In analysis I, a total of 132,850 patients were included (2978 children, 43,209 elderly, and 86,663 adults). Hypersensitivity reactions were significantly less frequent in children (0.47%) and elderly (0.38%) compared with adults (0.74%). The adjusted odds ratio (vs adults) for children was 0.58 (95% confidence interval, 0.34-0.98; P < 0.043), and that for the elderly was 0.51 (95% confidence interval, 0.43-0.61; P < 0.001), indicating a lower risk for both subpopulations as compared with adults. In analysis II, of the overall >288 million iopromide administrations, 5.87, 114.18, and 167.97 million administrations were administered to children, elderly, and adults, respectively. The reporting rate for HSRs in children (0.0114%) and elderly (0.0071%) was significantly lower as compared with adults (0.0143%) (P < 0.0001).

CONCLUSIONS

Hypersensitivity reactions to iopromide were significantly less frequent in children and elderly compared with adults.

Biological dosimetry after yttrium-90 citrate colloid radiosynoviorthesis

Radiosynoviorthesis (RSO) with the β-particle-emitting nuclide yttrium-90 is an established concept for the treatment of persistent synovitis of the knee joint. The aim of this study was to investigate the biological radiation effect on the basis of a characteristic radiation parameter. Patients, methods: After RSO procedures with yttrium-90 citrate colloid and subsequent immobilisation of the knee, blood specimens of 10 patients were collected immediately before RSO and 11 to 13 days after the intervention. The yield of dicentric chromosomes in the lymphocytes was determined exclusively in metaphases of the first cell cycle in vitro. In addition, activity leakage was measured by wholebody bremsstrahlung-scintigraphy. Results: No statistically significant increase in the number of dicentric chromosomes (26 before treatment and 34 after treatment) in 20 192 cells analyzed from the 20 blood samples could be found as a result of RSO. However, the analysis of at least 1000 cells per blood sample demonstrates a tendency for a biological radiation effect in the blood of patients on the basis of this characteristic radiation parameter. Two of the 10 RSO patients had undergone a second RSO using yttrium- 90 citrate, whereby one patient displayed activity transport out of the knee joint, amounting to 6 MBq. Only for him a radiation effect (about 130 mGy per single RSO) could be calculated by biological dosimetry. Conclusion: Since in general, based on the analysis of dicentric chromosomes in at least 1000 lymphocytes per individual, detection limits for groups of persons after long-term exposures to low-LET radiation of 50-100 mGy are possible, we assume that RSO with yttrium-90 should be associated with a low whole-body radiation exposure.

Safety and tolerability of iopromide intravascular use: a pooled analysis of three non-interventional studies in 132,012 patients

BACKGROUND

Determining the safety of contrast agents is challenging. In the absence of large controlled clinical trials, non-interventional (post-marketing surveillance) studies provide an opportunity to clearly investigate the safety profile of contrast agents.

PURPOSE

To assess the safety profile of iopromide in contrast-enhanced X-ray in clinical practice, using pooled data from three non-interventional studies.

MATERIAL AND METHODS

All studies were international, multicenter, non-interventional studies examining iopromide tolerability in clinical practice. Patients received iopromide (iodine concentrations of 300 mg/mL or 370 mg/mL) via intravenous or intra-arterial administration according to the diagnostic indication and in compliance with the local package insert.

RESULTS

In total, 132,012 patients (37 countries, >1600 centers) were included. Overall, 3823 patients (2.49%) reported an adverse drug reaction (ADR) and 1983 patients (1.50%) reported an ADR without tolerance indicators (injection site warmth, feeling hot or injection site pain, of mild intensity only). This is a similar rate to other low osmolar contrast media. In most patients, ADRs were mild (n = 2632; 1.99% of all patients) and did not require any action (n = 2799; 2.12% of all patients). ADRs were more common among women (n = 1680 [2.8%]) than men (n = 1586 [2.2%]) and among younger patients (<18 years: n = 98 [3.2%]) than older patients (18-49 years: n = 1261 [3.5%]; 50-69 years: n = 1224 [2.2%]; ≥70 years: n = 362 [1.5%]). The most common ADRs were injection site warmth/feeling hot, nausea/vomiting, and dysguesia. Forty-five serious ADRs were reported in 19 patients. ADRs were more common in at-risk patients (5.00%) than in the overall population.

CONCLUSION

This pooled analysis confirms the well-established good safety profile of iopromide in clinical practice in Asian and European countries and the USA.

Development of a physiologically based computational kidney model to describe the renal excretion of hydrophilic agents in rats

A physiologically based kidney model was developed to analyze the renal excretion and kidney exposure of hydrophilic agents, in particular contrast media, in rats. In order to study the influence of osmolality and viscosity changes, the model mechanistically represents urine concentration by water reabsorption in different segments of kidney tubules and viscosity dependent tubular fluid flow. The model was established using experimental data on the physiological steady state without administration of any contrast media or drugs. These data included the sodium and urea concentration gradient along the cortico-medullary axis, water reabsorption, urine flow, and sodium as well as urea urine concentrations for a normal hydration state. The model was evaluated by predicting the effects of mannitol and contrast media administration and comparing to experimental data on cortico-medullary concentration gradients, urine flow, urine viscosity, hydrostatic tubular pressures and single nephron glomerular filtration rate. Finally the model was used to analyze and compare typical examples of ionic and non-ionic monomeric as well as non-ionic dimeric contrast media with respect to their osmolality and viscosity. With the computational kidney model, urine flow depended mainly on osmolality, while osmolality and viscosity were important determinants for tubular hydrostatic pressure and kidney exposure. The low diuretic effect of dimeric contrast media in combination with their high intrinsic viscosity resulted in a high viscosity within the tubular fluid. In comparison to monomeric contrast media, this led to a higher increase in tubular pressure, to a reduction in glomerular filtration rate and tubular flow and to an increase in kidney exposure. The presented kidney model can be implemented into whole body physiologically based pharmacokinetic models and extended in order to simulate the renal excretion of lipophilic drugs which may also undergo active secretion and reabsorption.

Impact of iso- and low-osmolar iodinated contrast agents on BOLD and diffusion MRI in swine kidneys

PURPOSE

To assess whether functional MR imaging using blood-oxygenation level-dependent (BOLD) imaging and diffusion-weighted imaging demonstrate changes in renal oxygenation and apparent diffusion coefficient (ADC) in a pig model.

MATERIALS AND METHODS

After administration of either 1-g iodine/kg body weight low-osmolar iopromide or iso-osmolar iodixanol, 8 mini pigs underwent a series of repeated BOLD measurements (TR/TE 106/5.9-48.7 ms, slice thickness 4 mm) and diffusion-weighted imaging measurements (TR/TE 3900/79 ms, slice thickness 4 mm) for 1 hour at 1.5 T. In this intraindividual cross over study, the second contrast agent injection with the other iodinated contrast agent was performed at least 24 hours after the initial contrast agent injection. BOLD-based R2* values as indirect measures of the renal oxygenation were determined for the cortex, the inner medulla, and the outer medulla. ADC values were measured for the cortex and the whole kidney.

RESULTS

For both contrast agents, a drop in R2* was found in the cortex, which normalized after 55 minutes. In the outer medulla and particularly in the inner medulla, a decreased initial drop of R2* was encountered with both contrast agents, with a slow increase toward the baseline R2*. In the inner medulla, elevated R2* values were found with the iso-osmolar contrast agent only. The ADC revealed an initial increase, which slowly decayed over the measurement period. This finding was more pronounced for the cortex compared with the whole-kidney analysis.

CONCLUSION

Functional MR imaging of the kidneys demonstrates increased R2* in the inner medulla only after the administration of the iodixanol potentially indicating hypoxia and thus a pathomechanism of contrast-induced nephropathy.

Safety and diagnostic image quality of iopromide: results of a large non-interventional observational study of European and Asian patients (IMAGE)

BACKGROUND

Iodine-based contrast agents such as iopromide play a central role in improving the diagnostic quality of imaging modalities using ionizing radiation.

PURPOSE

To investigate the safety and diagnostic image quality of iopromide in the routine clinical setting.

MATERIAL AND METHODS

This was an international, multicenter, prospective, single-arm, non-interventional study (NIS). The study was performed in out- and inpatients in 738 study centers in 21 countries in Europe and Asia. Iopromide was administered in a routine manner, in compliance with the local package insert. The use of premedication was at the discretion of the attending physician. Case report forms for 44,835 patients were analyzed (57.4% men). The median age of the patients was 55 years.

RESULTS

For the vast majority of patients (94.8%), the contrast quality was rated as 'good' (55.8%) or 'excellent' (39.0%). For 1265 (2.8%) patients, there were reports of adverse drug reactions (ADRs) excluding tolerance indicators (TIs) (i.e. injection site warmth, feeling hot, or injection site pain of mild intensity). At least one ADR including TIs was reported in 2415 (5.4%) patients. There were 11 (0.02%) patients with serious ADRs, and no drug-related deaths. Events of injection site warmth and/or feeling hot were reported by 3.5%, nausea and/or vomiting by 0.96%, and urticaria, erythema, and/or rash by 0.54% of patients. Patients at risk for an acute idiosyncratic reaction (i.e. patients with a history of bronchial asthma, allergies, and/or contrast media reaction) had a higher incidence of ADRs compared with the overall study population. At-risk patients who did not receive premedication reported distinctly more ADRs compared with those who received premedication (12.0% versus 5.9%).

CONCLUSION

Iopromide was shown to be a well-tolerated contrast agent whose usage resulted in high image quality. No unknown ADRs were observed. Premedication with antiallergy drugs should be considered in at-risk patients.

Influence of the Fermi Energy on Si–H Vibrational Modes in Amorphous and Microcrystalline Silicon

The influence of boron and phosphorous doping and the effect of structural changes on hydrogen bonding in a-Si:H and µc-Si are investigated using Raman spectroscopy. Information on H bonding is obtained from Si-H stretching local vibrational modes (LVM's). In n-type and undoped a-Si:H the LVM's of isolated Si-H near 2000 cm−1 and clustered Si-H around 2100 cm−1 can be clearly distinguished. In heavily B doped a-Si:H, however, the LVM at 2100 cm−1 disappears. A structural change from a-Si:H to µc-Si gives rise to an additional mode centered at 1911 cm−1. Similar LVM's are observed in poly-Si containing platelets.

Viscosity of iodinated contrast agents during renal excretion

OBJECTIVE

Modern iodinated non-ionic contrast agents (CAs) can be classified based on their molecular structure into monomeric and dimeric CAs and have at comparable iodine concentrations a different viscosity and osmolality. During their renal excretion, CAs are concentrated in the renal tubuli which might enhance the viscosity difference between monomeric and dimeric CAs. The viscosity of a CA might have an underestimated importance for renal safety, as suggested by recent publications. In this study, we investigated the viscosities of CAs at the concentrations expected to be present in renal tubules. This concentration process was simulated in vitro using dialysis. Furthermore, we investigated urine viscosity and urine flow in rodents after administration of several non-ionic monomeric and dimeric CAs.

MATERIALS AND METHODS

To estimate the viscosity of the CAs in vivo, we performed an in vitro dialysis of monomeric and dimeric CAs at various physiological osmolalities of the renal tubulus (290, 400, 500, 700 and 1000 mOsm/kg H2O). Following the dialysis, the iodine concentrations and the viscosities of the CAs were determined. Furthermore, to investigate the concentration process in vivo, we measured the urine viscosity and the urine flow in Han Wister rats after the administration of Iopromide, Iohexol, Ioversol, Iomeprol, Iodixanol, and Iosimenol at comparable iodine concentrations. As a control, saline was injected at the same volume.

RESULTS

In vitro dialysis of the dimeric CA increased the iodine concentration and strongly increased the viscosity at all tested osmolalities. In contrast, for the monomeric agents an increase in concentration and viscosity was observed only at 700 as well 1000 mOsm/kg H2O but to a lesser extent. In summary, dialysis strongly enhanced the viscosity differences between the non-ionic monomeric and dimeric CAs. The administration of dimeric CAs leads to a strong increase in urine viscosity; this was not observed for the monomeric CAs. In contrast, a significantly higher urine flow was measured after the administration of the monomeric CAs as compared to the dimeric CAs.

CONCLUSION

We demonstrated that the viscosity differences between monomeric and dimeric CAs are strongly enhanced due to a concentration process of the CAs upon increasing osmolalities, a process which is likely to take place in a similar manner in the tubular system. This result suggests that the viscosity of the dimeric agents increases dramatically in vivo and gives a plausible explanation for measured enhancement of urine viscosity upon dimeric CA administration. On the other hand, the higher osmolality of the monomeric agents causes an osmodiuresis, indicated by a higher urine flow, which leads to a faster elimination of the CAs from the kidney.

The influence of x-ray contrast agents in computed tomography on the induction of dicentrics and gamma-H2AX foci in lymphocytes of human blood samples

The aim of this study was to investigate and quantify two biomarkers for radiation exposure (dicentrics and gamma-H2AX foci) in human lymphocytes after CT scans in the presence of an iodinated contrast agent. Blood samples from a healthy donor were exposed to CT scans in the absence or presence of iotrolan 300 at iodine concentrations of 5 or 50 mg ml(-1) blood. The samples were exposed to 0.025, 0.05, 0.1 and 1 Gy in a tissue equivalent body phantom. Chromosome aberration scoring and automated microscopic analysis of gamma-H2AX foci were performed in parts of the same samples. The theoretical physical dose enhancement factor (DEF) was calculated on the basis of the mass energy-absorption coefficients of iodine and blood and the photon energy spectrum of the CT tube. No significant differences in the yields of dicentrics and gamma-H2AX foci were observed in the absence or presence of 5 mg iodine ml(-1) blood up to 0.1 Gy, whereas at 1 Gy the yields were elevated for both biomarkers. At an iodine concentration of 50 mg ml(-1) serving as a positive control, a biological DEF of 9.5 +/- 1.4 and 2.3 +/- 0.5 was determined for dicentrics and gamma-H2AX foci, respectively. A physical DEF of 1.56 and 6.30 was calculated for 5 and 50 mg iodine ml(-1), respectively. Thus, it can be concluded that in the diagnostic dose range (radiation and contrast dose), no relevant biological dose-enhancing effect could be detected, whereas a clear biological dose-enhancing effect could be found for a contrast dose well outside the diagnostic CT range for the complete radiation dose range with both methods.

Dicentric chromosomes and gamma-H2AX foci formation in lymphocytes of human blood samples exposed to a CT scanner: a direct comparison of dose response relationships

Experiments using the induction of dicentric chromosomes (dicentrics) as well as the gamma-H2AX foci formation in lymphocytes of blood samples from a healthy donor were performed to directly evaluate the radiation sensitivity of both biological endpoints. For computed tomography scans at dose levels from 0.025 to 1 Gy, a linear-quadratic dose-response relationship for dicentrics and a linear dose-response relationship for gamma-H2AX foci were obtained. The coefficients of the dose-response relationship for dicentrics are alpha = (3.76 +/- 0.29) x 10(-2) Gy(-1) and beta = (5.54 +/- 0.45) x 10(-2) Gy(-2), the linear coefficient for gamma-H2AX foci is (7.38 +/- 0.11) Gy(-1). The findings indicate that scoring of dicentrics as well as microscopic analysis of gamma-H2AX foci are sensitive methods to quantify a radiation-induced biological damage at low doses. However, since gamma-H2AX foci can be partially repaired within a few hours, biological damages present for days or even months, which constitute the clinically relevant endpoints, can only be quantified reliably by scoring of chromosome aberrations. Thus currently the quantification of dicentrics or reciprocal translocations remains the recommended method for estimating the effect of exposures to low dose levels of radiation ('biological dosimetry'). However, owing to the high radiation sensitivity of the gamma-H2AX foci assay observed in the present study, further investigations on the effectiveness of low-linear energy transfer radiation qualities in producing gamma-H2AX foci in lymphocytes from healthy donors should be performed.

Long-term retention of gadolinium in the skin of rodents following the administration of gadolinium-based contrast agents

Several publications suggest a potential association between the administration of Gadolinium-based contrast agents (GBCAs) and the onset of a rare but serious disease, Nephrogenic Systemic Fibrosis (NSF). The aim of this study was to determine the elimination time-course of Gadolinium (Gd) from skin tissue after application of GBCAs in rats. Seven different marketed GBCAs were injected on five consecutive days at a dose of 2.5 mmol/kg bodyweight into the tail vein of Han-Wistar rats and the Gd concentrations were determined by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) in skin biopsies taken at various time-points up to a year after the last injection. Most of the administered Gd was eliminated from the skin within a time-period of about 2 months. However, the repeated administration of linear GBCAs resulted in long-term retention of a small portion of the administered Gd in the skin tissue of rats, with substantially higher values observed in animals treated with non-ionic linear agents than in those that received ionic linear GBCAs. Following treatment with macrocyclic GBCAs, Gd values in the skin were in the same range as observed in the controls from day 24 post-injection onwards. In summary, we observed a correlation between the complex stability of GBCAs and the amount of residual Gd in the skin up to a year after application of GBCAs.

Gadolinium-based contrast agents and their potential role in the pathogenesis of nephrogenic systemic fibrosis: the role of excess ligand

PURPOSE

To investigate the role of excess ligand present in gadolinium (Gd) -based contrast agents in the development of nephrogenic systemic fibrosis (NSF). Using a dosing regimen to simulate the exposure seen in patients with severe renal impairment, we investigated the effect of excess ligand on Gd-deposition and the depletion of endogenous ions.

MATERIALS AND METHODS

Gadodiamide and gadoversetamide were formulated with 0%, 5%, and 10% excess ligand. Forty-two, healthy, male Hannover Wistar rats received daily intravenous injections of each formulation over a period of 20 days. At the end of the study, histopathological analysis of the skin was performed and the concentrations of Gd, Zn, and Cu were measured in several tissues. The levels of Zn in the urine were also measured.

RESULTS

The most severe skin lesions were observed after injection of formulations containing 0% free ligand and in those animals with the highest Gd concentrations in the skin. There were no significant reductions in the levels of Zn or Cu observed in the skin; however, the levels of Zn in the urine were elevated following administration of formulations with the highest amount of excess ligand.

CONCLUSION

Our findings suggest that there is an inverse correlation between the amount of excess ligand present in Gd-containing contrast agents and the amount of Gd in the tissue, and further underline the importance of the inherent stability of these agents in the development of NSF.

Preclinical investigation to compare different gadolinium-based contrast agents regarding their propensity to release gadolinium in vivo and to trigger nephrogenic systemic fibrosis-like lesions

Recent reports suggest that nephrogenic systemic fibrosis (NSF) is associated with the administration of gadolinium (Gd)-based contrast agents (GBCAs) and in particular with the stability of the Gd-complex. The aim of this investigation was to compare GBCAs and their potential to trigger NSF. Forty-two healthy male rats received repeated intravenous injections of six different GBCAs at high doses to simulate the exposure seen in patients with severe renal dysfunction. Histopathological and immunohistochemical analysis of the skin was performed, and the concentrations of Gd, zinc and copper were measured in several tissues by inductive coupled plasma atomic emission spectroscopy. Macroscopic and histological skin changes similar to those seen in NSF patients were only observed in rats receiving Omniscan. In addition, very high concentrations of Gd were observed in the animals treated with Omniscan, and, to a lesser extent, in animals treated with OptiMARK. Significantly lower levels of Gd were found after the treatment with ionic linear agents and even less after the treatment with macrocyclic agents. The data in this investigation strongly suggest that the stability of the Gd-complex is a key factor for the development of NSF-like symptoms in this experimental setting.

Contrast-induced Nephropathy in Coronary Intervention

Collapse

Biological dosimetry after yttrium-90 citrate colloid radiosynoviorthesis

Radiosynoviorthesis (RSO) with the ss-particle-emitting nuclide yttrium-90 is an established concept for the treatment of persistent synovitis of the knee joint. The AIM of this study was to investigate the biological radiation effect on the basis of a characteristic radiation parameter.

PATIENTS, METHODS

After RSO procedures with yttrium-90 citrate colloid and subsequent immobilisation of the knee, blood specimens of 10 patients were collected immediately before RSO and 11 to 13 days after the intervention. The yield of dicentric chromosomes in the lymphocytes was determined exclusively in metaphases of the first cell cycle in vitro. In addition, activity leakage was measured by wholebody bremsstrahlung-scintigraphy.

RESULTS

No statistically significant increase in the number of dicentric chromosomes (26 before treatment and 34 after treatment) in 20 192 cells analyzed from the 20 blood samples could be found as a result of RSO. However, the analysis of at least 1000 cells per blood sample demonstrates a tendency for a biological radiation effect in the blood of patients on the basis of this characteristic radiation parameter. Two of the 10 RSO patients had undergone a second RSO using yttrium-90 citrate, whereby one patient displayed activity transport out of the knee joint, amounting to 6 MBq. Only for him a radiation effect (about 130 mGy per single RSO) could be calculated by biological dosimetry.

CONCLUSION

Since in general, based on the analysis of dicentric chromosomes in at least 1000 lymphocytes per individual, detection limits for groups of persons after long-term exposures to low-LET radiation of 50-100 mGy are possible, we assume that RSO with yttrium-90 should be associated with a low whole-body radiation exposure.