Comparative trial of Omnipaque 350 (iohexol) and Telebrix 350 (sodium-meglumine-ioxithalamate) in left ventriculography and coronary arteriography.

In a double-blind randomized trial, the hemodynamic and electrophysiologic effects of the low-osmolar nonionic contrast medium iohexol (Omnipaque) and the standard high-osmolar ionic monomer sodium-meglumine-ioxithalamate (Telebrix) at left ventricular angiography and selective coronary arteriography were evaluated. Sixty patients were divided into two groups of 30 patients; one group received Omnipaque in a dosage of 350 mgI/ml and the other group received Telebrix in a dosage of 350 mgI/ml. The Omnipaque showed significantly less effects on heart rate and myocardial contractility, and induced less electrophysiological changes than did Telebrix. However, there was a significant increase of 10% in the diameter of the left coronary artery following selective coronary injection with Telebrix, while Omnipaque induced practically no change in vessel diameter. All hemodynamic and electrophysiologic effects proved to be short-lasting. We conclude that ionic and nonionic agents are similarly efficacious in providing adequate images with minimal risk to the patient. However, the nonionic agents exert slightly more alterations in cardiac hemodynamics and in electrocardiographic intervals. The vasodilatory effect on coronary artery diameter by Telebrix may entail a more rapid clearance of contrast medium from the coronary circulation, which might be of some advantage over nonionic contrast media.     

Omnipaque and Urografin in left ventriculography and coronary arteriography. A randomised, double blind study

In order to compare tolerability and radiographic properties of Omnipaque (iohexol) 350 mg I/ml and Urografin (sodium meglumine diatrizoate) 76% (370 mg I/ml) in left ventriculography and coronary arteriography, a randomised, double-blind parallel study was conducted. ECG, heart rate, blood pressure, cardiac output, oxygen saturation, CK-MB, adverse reactions and opacification were recorded. Twenty-five patients received Omnipaque and 24 Urografin and all patients were included in the final material. Omnipaque was found to have less influence on haemodynamics than Urografin. Few adverse reactions were encountered in the entire study, but fewer after injections of Omnipaque than after Urografin. Equally good opacification was demonstrated for both media. Omnipaque was found well suited for cardioangiography and superior to standard ionic media.     

Clinical testing of omnipaque and amipaque in external carotid and vertebral angiography: randomized double-blind crossover study

Omnipaque, 300 mg l/ml, was compared with Amipaque, 300 mg l/ml, for cerebral angiography. Twelve patients were included in a randomized, double-blind, crossover study. Twenty comparisons were made in the external carotid and 21 in the vertebral artery, Both contrast media caused no or minor changes in blood pressure and heart rate. Good to excellent radiographic visualization of the cerebral arteries was obtained with both agents. The frequency of subjective reactions was almost equal, but the intensity of the reactions was less with Amipaque. No severe reactions were observed. Omnipaque is a more practical nonionic contrast medium than Amipaque because it is delivered in ready-to-use solutions.     

Iohexol and ioxaglate in peripheral angiography

A double-blind, cross-over trial of the non-ionic, low-osmolar contrast medium iohexol (Omnipaque) and the ionic, low-osmolar medium ioxaglate (Hexabrix) at concentrations of 300 mg I/ml was carried out in 107 consecutive patients with arterial insufficiency of the lower limbs. The purpose of the study was to observe possible 'carry-over' effects from any of the contrast media, and to evaluate patient discomfort such as pain, adverse reactions, or effect on peripheral blood pressure. No carry-over effect was seen. Ioxaglate caused less injection pain and heat sensations than iohexol, and showed less effect on the systemic blood pressure.     

Non-ionic contrast media: a comparison of iodine delivery rates during manual injection angiography

Iodine delivery rates (IDR) of five commonly used non-ionic contrast media were determined at room temperature (24 degrees C) and body temperature (37 degrees C). Contrast media of strength 300 mgI/ml were also evaluated at 50% dilution (150 mgI/ml) with N-saline. Iodine delivery differed significantly (p less than 0.005) between samples at room temperature: Omnipaque 350 (1163 mg/s) less than Niopam 370 (1311 mg/s) less than Omnipaque 300 (1422 mg/s) less than Niopam 300 (1635 mg/s) and Ultravist 300 (1636 mg/s). Niopam 300 and Ultravist 300 delivered 41% more iodine per second than Omnipaque 350 at room temperature. Similar differences were identified at body temperature, while delivery of individual media was on average 23.5% greater than at room temperature. No significant difference between iodine delivery rates of diluted media at room temperature or body temperature was identified. The results demonstrate that iodine delivery and hence vascular opacification are better achieved during hand-injection arteriography by using relatively low viscosity media such as Niopam 300 or Ultravist 300. In digital subtraction arteriography all 300 strength contrast media diluted to 150 strength are equally effective.     

Iohexol compared to metrizamide in cervical and thoracic myelography

Summary A randomized double blind study with iohexol (Omnipaque) and metrizamide (Amipaque) in cervical myelography was performed in 50 patients, 29 with iohexol and 21 with metrizamide. The myelographies were performed either with lumbar or with C₁–C₂ puncture in about equal groups, using 300 mg I/ml and 240 mg I/ml of the contrast media respectively. The image quality was equal with both contrast media, excellent in about 4/5 and good in 1/5 of the examinations. Subjective side effects were twice as frequent with metrizamide as with iohexol. The most frequent side effect was headache, occurring in 34% with iohexol and in 67% with metrizamide. Altogether 24% or the patients had EEG changes after iohexol as compared to 47% after metrizamide. All EEG changes were slight dysrythmia-except in three patients with spike activity after metrizamide. These were the only ones with mental reactions as well. It can be concluded that in this trial iohexol was better suited for cervical myelography than metrizamide.     

Omnipaque and urografin in arthrography of the knee

The first experience with Omnipaque in arthrography of the knee in patients is reported. Forty arthrographies were performed using either Omnipaque 350 mg I/ml or Urografin 370 mg I/ml at random. The low-osmolar non-ionic Omnipaque showed a tendency for pain of shorter duration and lower incidence of hydrops. A significantly lower incidence of complaints of tension and swelling and assessed reactive synovitis was demonstrated. Both contrast media produced excellent synovial coating on standard series, but Omnipaque showed a slower decrease in attenuation.     

Iohexol in coronary angiography. A double blind investigation

Iohexol 350 mg I/ml (Omnipaque) was compared with the routine contrast medium meglumine, Na-Ca-metrizoate 370 mg I/ml (Isopaque Coronar) in coronary angiography in 30 patients. A randomized, double blind, crossover design was employed. Angiographic image quality, ECG, heart rate, aortic blood pressure and adverse reactions were recorded. Excellent image quality was obtained with both media. Except for one single event of hypotension, only few and minor changes in the parameters measured were recorded. No distinct difference between the two media was found. Iohexol seems to be suitable for selective coronary angiography.     

Comparative double-blind investigation of meglumine metrizoate, metrizamide, and iohexol in carotid angiography

The new nonionic contrast medium iohexol (Omnipaque) was compared with its predecessor metrizamide (Amipaque) and with the conventional ionic medium meglumine metrizoate (Isopaque Cerebral) in carotid angiography using a double-blind crossover technique. The results indicated that iohexol and metrizamide caused less discomfort than the ionic medium. The circulatory effects of the three media were generally mild, and the diagnostic effectiveness was comparable when the iodine concentration was kept in the range of 280-300 mg I/ml.     

Comparison of low-osmolar contrast media in paediatric cardiac angiography

Sixty-two children investigated by cardiac angiography for a wide spectrum of congenital heart disease were randomly assigned to one of two groups, one for iohexol, 350 mg I/ml (Omnipaque, Nycomed UK Ltd) and one for iopamidol, 370 mg I/ml (Niopam, E. Merck Ltd). Changes in systolic pressure, end-diastolic pressure when the injection was made into a ventricle, heart rate and rhythm and plasma osmolality were assessed at 1 min and 3 min after the injection of contrast medium. The angiograms were subjectively assessed for angiographic quality. No significant differences were detected between the two groups.     

Clinical testing of Iohexol,Conray meglumine and Amipaque in cerebral angiography

Summary Iohexol 300 mg I/ml, Conray meglumine 282 mg I/ml and Amipaque 300 mg I/ml have been compared in a randomized double-blind cross over study in which one injection of Iohexol 300 mg I/ml and Conray meglumine 282 mg I/ml was made in the same artery (common and internal carotid artery) of the same patient, and one injection of Iohexol 300 mg I/ml and Amipaque 300 mg I/ml was made in another artery (external carotid artery and vertebral artery). All together 63 cerebral artery branches were examined in 27 patients, who served as their own controls. The effect of the contrast injections on the intraarterial blood pressure, pulse rate, ECG, circulatory rate and the patients' reactions were recorded under standardized conditions. The quality of the film was also evaluated. No significant difference was found in the cardiovascular effects after the injection of Iohexol or Conray meglumine into the common carotid or internal carotid. There was significantly less pain and sensation of warmth after the injection of Iohexol than after Conray meglumine 282. In the vertebral and the external carotid arteries, where a comparison between Iohexol and Amipaque was carried out, it was found that no significant difference in the cardiovascular effects occurred. There was less sensation of warmth after the injection of Amipaque into the vertebral artery than was caused by Iohexol. The degree of discomfort in form of pain reaction was the same for the two media, when these reactions occured. No serious side effects were observed.Read at the Annual Meeting of the Scandinavian Society of Neuroradiology, August 1981     

Myelography with a dimeric (iodixanol) and a monomeric (iohexol) contrast medium: a clinical multicentre comparative study

The purpose of this study was to evaluate and compare the radiographic efficacy and safety of iodixanol (Visipaque; 270 and 320 mg I/ml) and iohexol (Omnipaque; 300 mg I/ml) in myelography. The study was randomized, double-blind and comparative including 398 patients from five European university clinics. The radiographic visualisation was evaluated as poor, good or excellent. Adverse events were recorded by interviewing the patients after the myelography, and each patient was given a questionnaire to be returned after 1 week. In cervical myelography with cervical puncture more films with excellent quality was obtained after iodixanol 320 mgI/ml compared with iohexol 300 mgI/ml (p = 0.009). Also in lumbar myelography iodixanol 320 mgI/ml compared favourably with iohexol 300 mgI/ml (p = 0.006). The most frequent adverse event was headache, which occurred in 5–35 % of patients during the first 24 h and in 19–61 % within the first 7 days, depending on the centre. There was no difference in frequency and severity of the adverse effects between the contrast media. Received 13 March 1997; Revision received 29 December 1997; Accepted 5 January 1997     

Polysorbate 80 and low-osmolality water-soluble contrast medium enema in diagnosis and treatment of faecal obstruction in malignant phaeochromocytoma. Report of a case

Stercoral obstruction in a young woman with disseminated phaeochromocytoma was diagnosed and treated successfully using an enema of isosmolar iohexol (Omnipaque) and 1% polysorbate 80 (Tween 80) without complication. Surgical intervention was thus avoided. A low osmolality water-soluble contrast medium (iohexol 150 mg I/ml) with a wetting agent (1% Tween 80) was used because a barium suspension would have inspissated, exacerbating the constipation and a hyperosmolar contrast medium might have precipitated a hypertensive crisis and destabilized her critical salt and water balance.     

Pain in femoral arteriography. A double-blind, randomized, clinical study comparing safety and efficacy of the iso-osmolar iodixanol 270 mgI/ml and the low-osmolar iomeprol 300 mgI/ml in 9 European centers

PURPOSE: To compare the injection-associated pain and heat sensation after administration of the iso-osmolar contrast medium (IOCM) iodixanol (Visipaque trade mark 270 mg I/ml) and the low osmolar contrast medium (LOCM) iomeprol (Iomeron trade mark 300 mg I/ml) in femoral arteriography. MATERIAL AND METHODS: 352 patients received iodixanol or iomeprol in a prospective, double-blind, randomized, parallel-group clinical trial. The first injection during femoral arteriography (DSA with automated stepping) was standardized. Injection-associated pain and heat sensation, efficacy and safety up to 72 h were evaluated. RESULTS: The iodixanol group reported significant less injection-associated pain than the iomeprol group after the first injection (7.4% vs. 17.6%; p = 0.007), and after all injections (11% vs. 19.4%; p = 0.045). Iodixanol caused less heat sensation after the first injection (p = 0.007) and after all injections (p = 0.029). Heat sensations in the iodixanol group were less intense after all injections (p < 0.0001). No difference was found between the groups regarding the frequency of patients having adverse reactions (5.1% vs. 4%). CONCLUSION: The IOCM iodixanol caused significantly less frequent injection-associated pain and heat sensation than the LOCM iomeprol during femoral arteriography.     

Incidence of ventricular fibrillation during coronary arteriography in the rabbit. A comparative study of isotonic ioxaglate and iohexol

The incidence of major ECG changes, particularly ventricular fibrillation, was evaluated in rabbits during prolonged, selective right coronary injection of sodium/meglumine ioxaglate (Hexabrix 160) and iohexol (Omnipaque 140), two isotonic contrast media. The anesthetized animals (n = 12) per test solution) each received 1.5 ml of contrast material, delivered at a rate of 3 ml/minute. Both contrast media caused major ECG changes, which were reversible within seconds after administration. No fibrillation occurred with ioxaglate, but ventricular fibrillation was seen in seven animals given iohexol. There was a significant difference in the incidence of ventricular fibrillation between the contrast media (P less than .01). Both test solutions induced transient, more or less marked bradycardia, but without significant differences. The intracoronary injections produced similar decreases in blood pressure for both contrast agents. Reactive hypertension was observed only in those animals in which an episode of fibrillation occurred with iohexol. The causes underlying these effects are analyzed for both contrast agents.     

Addition of local anesthetics to contrast media. I. Effects on patient discomfort and hemodynamics in aortofemoral angiography

Effects of equiosmolar solutions (osmolality 1.35 mol/kg) of the ratio 1.5 contrast medium metrizoate (250 mg I/ml) containing either the local anesthetic mepivacaine or saline were evaluated on subjective discomfort, aortic blood pressure and heart rate in 17 patients referred for aortofemoral angiography due to intermittent claudication. Each patient was injected with 30 ml (15 ml/s) of each solution in random double-blind order. Each patient was then injected with 45 ml (12 ml/s) of the ratio 3 medium ioxaglate (320 mg I/ml, osmolality 0.58 ml/kg). Ioxaglate caused significantly less total discomfort, pain, heat, vocal reactions, involuntary movements and hemodynamic effects than metrizoate-mepivacaine and metrizoate-saline. The effects of the two metrizoate solutions did not differ significantly. Previous contradictory reports on the effects of anesthetics in contrast media were reviewed with regard to experimental design, different osmolality of the test and control solutions, premedication, and pH dependence of local anesthetics. Ratio 3 media are recommended because they produce a more reliable relief of patient discomfort and fewer hemodynamic changes than the addition of local anesthetics to ratio 1.5 media.     

High dose urography in patients with renal failure. A double blind investigation of iohexol and metrizoate

The new non-ionic contrast medium iohexol 350 mg I/ml was compared with the ionic contrast medium metrizoate 350 mg I/ml in a double blind, two-group urographic study performed on 20 patients with stable, impaired renal function. A dose of contrast medium of 500 mg I/kg body weight was given to each patient. Iohexol resulted in significantly fewer subjective adverse reactions than metrizoate. A similar image quality was obtained with the two contrast media. No clinically significant difference existed between the two contrast media with respect to influence on blood pressure, pulse or clinical chemical parameters. A tendency to deterioration of renal function after urography was found in both groups, but no difference of statistical significance existed between the two contrast media with respect to possible nephrotoxicity. Inadequate hydration may have been partly responsible for the nephrotoxic effect of the urographic procedure.     

Effect of an iso-osmolar contrast medium on pulmonary arterial pressure at pulmonary angiography

A clinical comparison of the effects on pulmonary arterial pressure induced by contrast media with various osmolalities, iohexol 140 mg I/ml (300 mosm/kg H2O), iohexol 300 mg I/ml (690 mosm/kg H2O), and diatrizoate 292 mg I/ml (1480 mosm/kg H2O) following selective pulmonary angiography was made in 12 patients with normal pulmonary arterial pressure. A double-blind crossover study was performed and the contrast media were administered in random order. The pulmonary arterial pressure was recorded continuously before, during, and for 3 min after the injection. The effect of iohexol 140 on the pulmonary arterial pressure was significantly less marked than that of diatrizoate 292, whereas no statistical significance was shown between iohexol 140 and iohexol 300. These results indicate that iso-osmolar contrast medium (iohexol 140), as well as iohexol 300, would be better tolerated than diatrizoate 292, and is therefore a safer contrast medium for selective pulmonary angiography.     

Clinical experience with iopamidol for myelography

Within 20 months 145 ascending thoracocervical myelographies and 155 lumbar myelographies with the nonionic water-soluble contrast medium iopamidol were performed. The iodine concentration given was 250 mg I/ml or 200 mg I/ml respectively. The total iodine never exceeded 2.5 g (8-10 ml). Image quality was assessed in terms of diagnostic value having experience of more than 1,000 myelographies using metrizamide. Picture quality was similar to metrizamide of equal iodine concentration. In 35 patients electroencephalography (EEG) was recorded before and after myelography with iopamidol 250. No changes that could be referred to the contrast medium were seen. There were no adverse reactions to lumbar myelography other than those following the lumbar puncture. In thoracocervical myelography mild and transient side effects occurred in 41 (28.3%). The most common were headache (41 cases), nausea (12), radicular pain (10), and dizziness (five). General seizures and psychopathologic symptoms were not observed.     

The toxicity of the non-ionic water-soluble contrast media iohexol and metrizamide (Amipaque) in selective vertebral angiography

Summary Selective left vertebral angiography was carried out in 25 rabbits comparing the toxic effects of iohexol and metrizamide (Amipaque). The iodine concentration for iohexol was 280 and 350 mg/ml and for metrizamide 350 mg/ml. Short general convulsions were seen in many of the animals with iohexol in the concentration of 350 mg iodine/ml. Cardiovascular reactions were seen with both contrast media, but were more marked with iohexol than with metrizamide in the concentration of 350 mg iodine/ml. Both iohexol and metrizamide are far less toxic than the ionic contrast medium metrizoate, but metrizamide seems to be less toxic than iohexol in vertebral angiography.