Nonionic Monomeric Contrast Medium Research Articles

Urine viscosity after injections of iotrolan or iomeprol.

Previous observations in rats caused us to speculate whether the injection of iotrolan, a nonionic dimeric contrast medium (CM), would increase urine viscosity enough to obstruct urine outflow in the collecting duct. The urine viscosity in dogs was measured directly with a viscosimeter after injections of iotrolan or of iomeprol, a nonionic monomeric CM. The injection of iotrolan increased urine viscosity considerably whereas iomeprol had little effect on this variable. The osmolality-dependent adverse reactions of CM have previously been emphasized but viscosity-dependent adverse reactions must also be considered when the CM is a polymer with a low osmolality.

Renal CT after intravenous injection of nonionic dimeric or nonionic monomeric contrast media in healthy volunteers

Renal CT after intravenous injection of nonionic dimeric or nonionic monomeric contrast media in healthy volunteers

Safety profile of new non-ionic contrast media: renal tolerance

The possible nephrotoxic potential of X-ray contrast media is one of the main concerns when testing new compounds. Iomeprol is a new nonionic monomeric contrast medium which has been tested during preclinical studies and clinical trials. Preclinical studies showed that the product has a renal tolerance comparable to that of other nonionic contrast media (iopamidol and iohexol) and less effects on renal histology than dimers like iodixanol and iotrolan. The clinical safety of the product has been evaluated during diagnostic procedures in more than 8000 patients and in particular renal function was studied in 988 patients. Results showed that iomeprol did not cause any alterations of clinical laboratory indices for renal function nor any cases of acute renal insufficiency.

Effect of iodixanol on in vitro bleeding time

Both monomeric and dimeric ionic radio contrast media (CM) have been shown to be more anticoagulant than nonionic monomeric CM. Iodixanol is a relatively new nonionic dimeric contrast medium. We investigated whether the dimeric structure of iodixanol would produce the same level of anticoagulation that has been observed using nonionic monomeric CM. We used a global screening device that operates under physiologic flow conditions to monitor the effects of iodixanol on in vitro bleeding time (IVBT). This flow dynamic technique perfuses nonanticoagulated whole blood through a hollow fiber device. A leak in the fiber is created by a precision needle, and the resulting pressure fluctuations within the fiber are monitored to examine the ability of the hemostatic system to close the leak by forming a stable platelet plug. In 20 donors, iodixanol (25% CM/blood, v/v) was shown to lengthen the mean IVBT (18.74 min) compared with the normal blood mean IVBT (4.24 min). The addition of dimeric iodixanol to normal blood affects the IVBT in the same manner as nonionic monomeric CM (ioversol, iopamidol, and iohexol).

Contrast Enhancement of the Upper Abdomen Evaluated BY CT

The non-ionic monomeric contrast media iopamidol and iohexol were compared concerning enhancement in the organs of the upper abdomen in CT. The average peak enhancement above the base line for the 2 contrast media in the liver, vena cava, aorta and spleen was calculated. No difference between the contrast media was found with regard to increase in contrast enhancement. No correlation between the peak enhancement and body weight and body surface was found with either of the 2 contrast media.

Effects on Erythrocyte Aggregation and Blood Coagulation from Iohexol Solutions with and without Sodium Chloride

Solutions of the nonionic monomeric contrast medium iohexol (300 mg I/ml) with and without added NaCl were investigated for effects on red blood cell aggregation and blood coagulation. Three volumes of a test solution were mixed in test tubes with one volume of human blood. During 30 min samples of the mixture were taken for investigation. Six test solutions were used: 1) iohexol, 2) iohexol+glucose 280 mM, 3) iohexol+NaCl 150 mM, 4) glucose 280 mM, 5) glucose 140 mM+NaCl 75 mM, 6) NaCl 150 mM. Test solutions with NaCl caused no aggregation. Test solutions without NaCl always caused macroscopic red cell aggregates. These aggregates always disappeared when saline was added to the sample. The macroscopic red cell aggregates could be dispersed to microscopic aggregates by shaking the test tubes. During the next 30 min macroscopic aggregates returned in the glucose solution but not in the iohexol solutions. In 30 min, blood mixed with iohexol solutions never coagulated while blood layered on top of the same iohexol solutions always coagulated. Blood mixed with solutions 5 and 6, both without iohexol, always coagulated. It is concluded that adding 150 mM NaCl to iohexol did not eliminate its ability to antico-agulate whole blood, but inhibited its ability to aggregate red cells. This inhibition was not caused by the osmotic effects of the added NaCl.

Effects on Erythrocyte Aggregation and Blood Coagulation from Iohexol Solutions with and without Sodium Chloride

Solutions of the nonionic monomeric contrast medium iohexol (300 mg I/ml) with and without added NaCl were investigated for effects on red blood cell aggregation and blood coagulation. Three volumes of a test solution were mixed in test tubes with one volume of human blood. During 30 min samples of the mixture were taken for investigation. Six test solutions were used: 1) iohexol, 2) iohexol+glucose 280 mM, 3) iohexol+NaCl 150 mM, 4) glucose 280 mM, 5) glucose 140 mM+NaCl 75 mM, 6) NaCl 150 mM. Test solutions with NaCl caused no aggregation. Test solutions without NaCl always caused macroscopic red cell aggregates. These aggregates always disappeared when saline was added to the sample. The macroscopic red cell aggregates could be dispersed to microscopic aggregates by shaking the test tubes. During the next 30 min macroscopic aggregates returned in the glucose solution but not in the iohexol solutions. In 30 min, blood mixed with iohexol solutions never coagulated while blood layered on top of the same i...

Effects on Erythrocyte Aggregation and Blood Coagulation from Iohexol Solutions with and without Sodium Chloride

Solutions of the nonionic monomeric contrast medium iohexol (300 mg I/ml) with and without added NaCl were investigated for effects on red blood cell aggregation and blood coagulation. Three volumes of a test solution were mixed in test tubes with one volume of human blood. During 30 min samples of the mixture were taken for investigation. Six test solutions were used: 1) iohexol, 2) iohexol+glucose 280 mM, 3) iohexol+NaCl 150 mM, 4) glucose 280 mM, 5) glucose 140 mM+NaCl 75 mM, 6) NaCl 150 mM. Test solutions with NaCl caused no aggregation. Test solutions without NaCl always caused macroscopic red cell aggregates. These aggregates always disappeared when saline was added to the sample. The macroscopic red cell aggregates could be dispersed to microscopic aggregates by shaking the test tubes. During the next 30 min macroscopic aggregates returned in the glucose solution but not in the iohexol solutions. In 30 min, blood mixed with iohexol solutions never coagulated while blood layered on top of the same iohexol solutions always coagulated. Blood mixed with solutions 5 and 6, both without iohexol, always coagulated. It is concluded that adding 150 mM NaCl to iohexol did not eliminate its ability to anticoagulate whole blood, but inhibited its ability to aggregate red cells. This inhibition was not caused by the osmotic effects of the added NaCl.

Contrast Enhancement of the Upper Abdomen Evaluated by CT

The non-ionic monomeric contrast media iopamidol and iohexol were compared concerning enhancement in the organs of the upper abdomen in CT. The average peak enhancement above the base line for the 2 contrast media in the liver, vena cava, aorta and spleen was calculated. No difference between the contrast media was found with regard to increase in contrast enhancement. No correlation between the peak enhancement and body weight and body surface was found with either of the 2 contrast media.

Contrast Enhancement of the Upper Abdomen Evaluated by CT

The non-ionic monomeric contrast media iopamidol and iohexol were compared concerning enhancement in the organs of the upper abdomen in CT. The average peak enhancement above the base line for the 2 contrast media in the liver, vena cava, aorta and spleen was calculated. No difference between the contrast media was found with regard to increase in contrast enhancement. No correlation between the peak enhancement and body weight and body surface was found with either of the 2 contrast media.

Safety and Efficacy of Iopromide in Cerebral Arteriography

Iopromide is a new nonionic monomeric contrast medium for cerebral arteriography. This agent has been approved for sale in over 45 countries; however, it is still undergoing clinical review in the United States. This study evaluated the safety and efficacy of iopromide in comparison with two other nonionic contrast media. A total of 173 patients participated in the study, which was prospective, double-blind, and randomized. In two centers, patients received iopromide or iohexol; in the other three centers, patients received iopromide or iopamidol. Adverse events were monitored by investigators, and efficacy was evaluated by grading the radiographic images. Most adverse events were mild or moderate in severity; all resolved completely. Twenty-one percent of patients given iopromide were reported to have a drug-related adverse event, versus 44% of patients given a comparator. No statistically significant difference emerged between iopromide and the comparators with regard to efficacy. These study results indicate that iopromide is a safe and effective contrast medium for cerebral angiography.

Sodium Addition and/or Oxygen Saturation of Iohexol during Normal and Reduced Perfusion Pressure

The influence on contractile force (CF) and the propensity for ventricular fibrillation (VF) from infusing the non-ionic contrast medium iohexol during normal (75 cm H2O) and reduced perfusion pressure (35 cm H2O) were investigated in the isolated rabbit heart. Both during normal and reduced perfusion pressure iohexol (150 mg I/ml) with oxygen saturation caused a smaller reduction of CF than iohexol without oxygen. During reduced pressure iohexol with sodium addition (28 mM NaCl) caused less depression of CF than iohexol without sodium. The combination of sodium addition and oxygen saturation had the least influence on CF. Iohexol (350 mg I/ml) without sodium had a similar fibrillatory propensity during both normal and reduced pressure. Enriching iohexol with 28 mM NaCl decreased the risk of VF. The decrease was similar during both normal and reduced pressure. The risk of VF from oxygen saturation of iohexol (350 mg I/ml, without sodium) was similar during both normal and reduced pressure. It is concluded that a small addition of sodium and/or oxygen saturation of a non-ionic monomeric contrast medium have beneficial effects on the heart both during normal perfusion pressure and during ischemia.

The use of urinary N-acetyl-β- D-glucosaminidase (NAG) for the detection of contrast-media-induced ‘osmotic nephrosis’ in rats

Excretion of urinary N-acetyl-β-glucosaminidase (NAG), lactate dehydrogenase (LDH), alkaline phosphatase (ALP) and γ-glutamyltransferase (γ-GT) was studied following single intravenous administrations of a non-ionic monomeric contrast medium (iohexol) at doses of 5.0, 7.5, 10.0 and 12.5 g iodine/kg body wt in rats. Measurements of urinary enzymes, serum urea nitrogen and serum creatinine were carried out on the 2nd, 3rd, 4th and 8th days after treatment. Histological examinations of kidneys were performed on days 3 and 8. From 5.0 g iodine/k onwards urinary NAG showed a dose-dependent and significant (multiple comparison, α = 0.05) increase in the first 18-h urine samples after application. A significant increase in urinary LDH could be observed only at the highest dose of 12.5 g iodine/kg. All other biochemical parameters showed no differences when compared to the control group. The dose-dependent increase in lysosomal NAG correlated with the histological findings i.e. there was dose-dependent vacuolization of proximal tubular cells, so-called ‘osmotic nephrosis’.

Reduction of the Risk of Ventricular Fibrillation in the Isolated Rabbit Heart by Small Additions of Electrolytes to Non-Ionic Monomeric Contrast Media

Perfusion of the isolated rabbit heart with solutions (350 mg I/ml) of the non-ionic contrast media iohexol and iopentol, both containing NaCl (20 mmol/l), caused a significantly lower frequency of ventricular fibrillation (VF) than solutions without NaCl. Iohexol or iopentol with NaCl (10 mmol/l) caused an intermediate frequency of VF. Iohexol with 10 or 20 mmol NaCl/l caused about the same frequency of VF as iohexol solutions with about the same total electrolyte concentration but with electrolyte composition as that of Krebs' solution. At 320 mg I/ml, solutions of iohexol (20 mmol NaCl/l), iodixanol (20 mmol NaCl/l) and ioxaglate (155 mmol Na/l) all produced a significantly lower frequency of VF than iohexol without NaCl. Ioxaglate caused the largest and iodixanol the smallest decrease in contractile force of the media. The investigation suggests that the small risk of VF from non-ionic monomeric media can be further reduced by adding a small amount of sodium chloride or of the electrolytes of Krebs' solution.

Reduction of the Risk of Ventricular Fibrillation in the Isolated Rabbit Heart by Small Additions of Electrolytes to Non-Ionic Monomeric Contrast Media

Reduction of the Risk of Ventricular Fibrillation in the Isolated Rabbit Heart by Small Additions of Electrolytes to Non-Ionic Monomeric Contrast Media