Assessment of the side-effects of iomeprol

Acute Adverse Reactions to Nonionic Iodinated Contrast Media: A Meta-Analysis

OBJECTIVES

We aimed to meta-analytically compare the incidence of acute adverse reactions (AARs) to nonionic iodinated contrast media (ICM) according to the type of ICM in patients who underwent radiologic examinations with administration of ICM via intravascular route.

MATERIALS AND METHODS

A systematic literature search identified studies evaluating the incidence of AARs to 7 nonionic ICM (iobitridol, iohexol, iomeprol, iopamidol, iopromide, ioversol, and iodixanol) with extractable outcomes. These outcomes were pooled using a random-effects model, and the effect of ICM type on the incidence of overall and severe AARs was evaluated using meta-regression analysis.

RESULTS

Thirty studies with 1,360,488 exposures to ICM were included. The pooled incidences of overall and severe AARs to nonionic ICM were 1.03% (95% confidence interval [CI], 0.81%-1.30%; I = 0.99) and 0.0141% (95% CI, 0.0108%-0.0183%; I = 0.56), respectively. Iomeprol had the highest overall AAR incidence (1.74%; 95% CI, 0.79%-3.76%; I = 0.99), followed by iohexol (1.21%; 95% CI, 0.67%-2.17%; I = 0.99), iopamidol (1.10%; 95% CI, 0.60%-2.03%; I = 0.99), ioversol (0.88%; 95% CI, 0.43%-1.83%; I = 0.96), iodixanol (0.85%; 95% CI, 0.36%-1.95%; I = 0.99), iopromide (0.82%; 95% CI, 0.43%-1.55%; I = 0.99), and iobitridol (0.77%; 95% CI, 0.36%-1.62%; I = 0.99). Multivariable meta-regression analysis revealed that study design (P = 0.0014) and premedication (P = 0.0230) were statistically significant determinants affecting the incidence of overall AARs. Iodinated contrast media type did not affect the incidence of overall and severe AARs (P = 0.1453 and 0.4265, each).

CONCLUSIONS

The varying pooled incidences of overall and severe AARs to specific types of nonionic ICM do not remain as significant after adjusting confounders. Our results may support nonrestriction of certain types of nonionic ICM in the context of AAR avoidance.

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.

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.

Hemodynamic Effects of Monomeric Nonionic Contrast Media in Pulmonary Angiography in Chronic Thromboembolic Pulmonary Hypertension

OBJECTIVE

The purpose of this study was to investigate the hemodynamic safety of the monomeric nonionic contrast agent iomeprol for selective pulmonary angiography in chronic thromboembolic pulmonary hypertension (CTPH), and to investigate the effect of periinterventional oxygen administration.

SUBJECTS AND METHODS

Selective pulmonary digital subtraction angiography was performed in 94 patients with CTPH using six bolus injections of iomeprol (posteroanterior, oblique, and lateral projections; both pulmonary arteries; iomeprol, 25 mL at 13 mL/s). Hemodynamics were obtained with Swan-Ganz catheters, and systolic pulmonary artery pressure (PAsyst) was classified into one of three groups: 30 mm Hg or less (control group), greater than 30 but less than or equal to 60 mm Hg (group 1, moderate pulmonary hypertension), and greater than 60 mm Hg (group 2, severe pulmonary hypertension).

RESULTS

At baseline, values for PAsyst were 21.4 +/- 2.3 (control group, n = 8), 49.8+/- 8.5 (group 1, n = 18), and 86.5 +/- 18.9 (group 2, n = 68) mm Hg (p < 0.001). Pulmonary vascular resistance indexes (PVRI) were 222 +/- 105 (control), 703 +/- 364 (group 1), and 1,582 +/- 562 (group 2) dyne x s x cm(-5) x m2 (p < 0.001). The mean cardiac indexes were 3.1 (control), 2.8 (group 1), and 2.3 (group 2) L/min/m2 (p < 0.05). Pulmonary capillary wedge pressure (PCw) indicated healthy left heart function. Periinterventional oxygen inhalation improved oxygen saturation in all groups and slightly reduced pulmonary artery pressure and heart rate. Online measurement of pulmonary artery pressure during contrast bolus injection for angiography showed only a minor increase, predominantly in severe pulmonary hypertension (triangle up [difference] PAsyst: 1.3 +/- 1.9 [control], 2.9 +/- 3.4 [group 1], and 3.8 +/- 4.5 [group 2] mm Hg [p < 0.001]). After completion of angiography, right atrial pressure (RAP) and PAsyst were moderately increased: triangle up RAP: 1.4 (control), 2.6 (group 1, p < 0.001), and 3.0 (group 2, p < 0.001) mm Hg; triangle up PAsyst: 3.2 (control), 7.7 (group 1, p < 0.01), and 8.5 (group 2) mm Hg (p < 0.001). PVRI was significantly higher in group 2 (triangle up PVRI: 188 dyne x s x cm(-5) x m2, p < 0.001).

CONCLUSION

Selective pulmonary angiography using iomeprol is safe without critical pressure peaks during selective contrast bolus injection or significant hemodynamic derangement in severe CTPH. Periinterventional oxygen inhalation improved pulmonary circulation.

Iodinated radiographic contrast media inhibit the capacitative calcium entry into smooth muscle cells of the swine renal artery

RATIONALE AND OBJECTIVES

To investigate whether nonionic, iodinated, radiographic contrast media (RCM) could modulate calcium release from or calcium entry into smooth muscle cells of the swine renal artery.

METHODS

Intracellular calcium concentrations of isolated myocytes loaded with the calcium-sensitive dye fluo-3 were analyzed using a fluorescence imaging system. Calcium signals were compared with isometric contractions of vascular segments in an organ bath. The effects of the triiodinated monomer iomeprol were compared with those of a mannitol solution.

RESULTS

Stimulation of alpha-receptors by phenylephrine caused a biphasic calcium signal. Transient liberation of calcium from intracellular stores triggered the sustained entry of extracellular calcium (capacitative entry). Iomeprol and mannitol slightly inhibited the initial transient spike to the same extent. The calcium influx was reversibly inhibited by RCM by about 50%. Up to a concentration of 40 mmol/L, the inhibition induced by iomeprol was significantly higher than that induced by mannitol (P < 0.05-0.01). In isolated arterial segments, relaxation of the contraction phase depending on the calcium influx was significantly higher with the RCM than with mannitol (P < 0.01).

CONCLUSIONS

Vasodilatation by CM is associated with a reduction in the capacitative entry of calcium. The mechanism of this effect is not clear, but it can be ruled out that it is mainly due to the high osmolarity of these compounds.

Iomeprol: current and future profile of a radiocontrast agent

RATIONALE AND OBJECTIVES

To review the safety and efficacy profiles of iomeprol by examining the most indicative comparative clinical studies of iomeprol with widely used low-osmolar ionic or nonionic contrast agents, and to illustrate the recent development in iomeprol liposomal formulations for liver imaging and intravascular enhancement.

METHODS

Randomized, double-blind, comparative studies were performed of iomeprol versus iopamidol, iopromide, ioxaglate, iopentol, iodixanol, ioversol, and iohexol. In all studies, safety controls included pre- and postadministration physical examinations, monitoring of vital signs, electrocardiography, clinical laboratory investigations, and 24- or 72-hour postadministration monitoring of patients for adverse events. Technically adequate images were rated for diagnostic efficacy by masked assessors.

RESULTS

Iomeprol showed similar safety and diagnostic efficacy compared with the nonionic monomers iopamidol, iohexol, and ioversol, and no statistically significant differences were observed. No differences in diagnostic efficacy between iomeprol and iopromide were observed, but in one study on 1,200 patients, the incidence of adverse events and adverse reactions was significantly higher with iopromide than with iomeprol. Iomeprol caused significantly less heat/pain than iopentol in one study; it showed similar safety and tolerability to the nonionic dimer iodixanol, the two agents causing no or modest, superimposable pain and heat sensation at injection and showing similar renal tolerability after intra-arterial injection. A comparison of iomeprol versus ionic dimer ioxaglate in 2,000 patients undergoing percutaneous coronary interventions showed that the incidence of thrombus-related events was similar with the two agents, but ioxaglate caused a significantly higher incidence of allergy-like reactions. First results with iomeprol-containing liposomal formulations show that these agents may facilitate the CT assessment of intrahepatic malignancies and CT angiography procedures.

CONCLUSIONS

The overall results of numerous randomized, double-blind, comparative clinical studies in a variety of indications show that the diagnostic efficacy of iomeprol solutions does not differ significantly from that of the low-osmolar contrast media available on the marketplace when similar iodine strengths are used, although iomeprol may have better tolerability and safety than the ionic dimer and some of the nonionic monomers in selective applications. First results obtained with iomeprol-containing liposomal formulations are promising and may foster additional clinical testing.

Iomeprol: a review of its use as a contrast medium

Iomeprol is a nonionic, monomeric iodinated contrast medium. Unlike the older ionic agents, iomeprol has low chemotoxicity, osmolality and viscosity and high water solubility. Compared with other nonionic contrast media, the osmolality and viscosity are lower and the water solubility is reported to be higher with iomeprol. Most radiographs (about 67 to 100%) obtained with iomeprol (containing 150 to 400 mg/ml of iodine) were of good or excellent quality in noncomparative and comparative trials recruiting 40 to 6127 patients undergoing various radiographic procedures. As expected, the diagnostic efficacy of iomeprol did not differ significantly from that of other nonionic agents (iopamidol, iopromide, iohexol and iotrolan). Iomeprol (containing 150 to 400 mg/ml of iodine) was well tolerated in clinical trials. Most adverse events were transient and of mild to moderate intensity and were similar to those observed with other contrast media. The overall incidence of adverse events ranged from 3 to 49.7% and mainly included localised pain (< or =6%) and heat sensations (8 to 45%), taste disturbances (3 to 27%) and various pseudoallergic reactions (< or =20% for each type of event). The incidence of heat or pain and taste disturbances with iomeprol was similar to that observed with iopromide and iopamidol. Pain (but not heat sensations) was reported significantly less frequently and taste disturbances reported significantly more frequently with iomeprol than with iohexol in a comparative trial. Pseudoallergic reactions (such as nausea, vomiting, skin reactions, dizziness, headache) were significantly less common with iomeprol than with ioxaglate and occurred at a similar frequency to that with iopromide and iopamidol. Cardiovascular events were rarely observed with iomeprol. Currently available iomeprol solutions contain a range of iodine concentrations (150 to 400 mg/ml) and are approved for a wide variety of diagnostic procedures. Iomeprol solutions are chemically stable which negates the need for chelating agents. Formulations of this agent are therefore the first not to contain edetic acid (EDTA).

CONCLUSIONS

Iomeprol shows equivalent diagnostic efficacy, and a similar adverse event profile, to that of other nonionic contrast media. The availability of a range of iodine concentrations enables iomeprol to be used in a variety of diagnostic procedures. Iomeprol, like others in its class, is suitable for use in diagnostic imaging.

Iomeprol versus iopromide for intravenous urography

Iomeprol (B16880) is a new non-ionic tri-iodinated radiographic contrast medium. It was the aim of this double blind randomized phase III clinical trial to compare the local and systemic tolerance of iomeprol-300 (300 mg I ml-1) with the commercially available iopromide-300 (300 mg I ml-1) in a group of 198 patients needing intravenous urography. The contrast medium was injected rapidly into an antecubital vein within 2-3 min in most cases, using a standard dosage of 1 ml kg-1 body weight. The proportion of patients with an allergic diathesis was 25% in the iomeprol group and 17.3% in the iopromide group. There were no life-threatening adverse reactions. Eight patients (8%) receiving iomeprol and 6 (6.1%) receiving iopromide had a sensation of heat related to the injection of contrast medium. Only one patient (1%) in the iomeprol group and two patients (2%) in the iopromide group noted pain on injection. Although the incidence of all other side-effects was relatively high (7% after iomeprol and 11.2% after iopromide) these reactions were generally harmless. The most common symptom was nausea and/or vomiting, which occurred with the same incidence (5%) in both groups. Only one patient in each group developed urticaria or erythema. Vital parameters remained essentially unchanged in all patients. The results suggest that iomeprol is a safe contrast medium, with a tendency to produce fewer side effects than iopromide, which is known to be particularly well tolerated.

Clinical utility and safety profile of iomeprol

Iomeprol is a new triiodinated, nonionic radiographic contrast agent prepared for injection at a number of concentrations (150, 200, 250, 300, 350 and 400 mgI/ml), each of which has osmolality and viscosity properties that are more favourable than other current nonionic monomers at the same iodine concentrations. Pharmaco-toxicological studies in animals have demonstrated that the molecular toxicity of iomeprol is very low. Intensive monitoring of vital, electro-physiological, and biochemical parameters in clinical studies have shown that iomeprol does not have clinically significant effects on the more important body systems and functions. Out of 7799 patients to whom iomeprol was administered, adverse events were observed in only 437 (5.6%). Of these events, the majority were rated as mild. In double-blind controlled clinical studies the contrast efficacy of iomeprol was shown to be as good as that of reference contrast media. The good efficacy was confirmed in a very large number of uncontrolled studies.