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Updated: Aug 8, 2026
A High-throughput Method for Measurement of Glomerular Filtration Rate in Conscious Mice
Published on: May 10, 2013
Lopromide one-sample clearance as a measure of glomerular filtration rate
Nils Hackstein1, Alexander C Langheinrich, Wigbert S Rau
1Department of Diagnostic Radiology, Justus-Liebig Universität Giessen, Germany. Nils.Hackstein@radiol.med.uni-giessen.de
Insights
Accurate iopromide plasma clearance can be determined with a single blood sample. The optimal time for this blood draw is between 270 and 285 minutes postinjection for reliable pharmacokinetic analysis.
Area of Science:
- Pharmacokinetics
- Radiology
- Medical Imaging
Background:
- Iopromide is a contrast agent used in computed tomography (CT).
- Accurate pharmacokinetic analysis, including plasma clearance, is crucial for understanding drug behavior and optimizing dosage.
- Traditional methods for calculating plasma clearance often require multiple blood samples, which can be inconvenient.
Purpose of the Study:
- To analyze the pharmacokinetics of iopromide using a two-compartment model.
- To determine the optimal time point for a single blood sample to accurately calculate iopromide plasma clearance.
Main Methods:
- Plasma iodine concentration was measured in 62 adult patients up to 8 hours after receiving 120 ml of iopromide for CT scans.
- A two-exponential function was fitted to the data using a weighted least error square method.
- One-sample clearance was calculated and compared against a reference method and established formulas for Tc99m-DTPA.
Main Results:
- The total distribution volume of iopromide was 0.242 L/kg.
- A high correlation was observed between one-sample and two-sample clearance methods.
- The best estimation of iopromide plasma clearance was achieved with a single sample taken at 270 or 285 minutes postinjection, with a standard deviation of 5.8 ml/min.
Conclusions:
- One-sample plasma clearance of iopromide can be reliably calculated with minimal error using a single blood sample at a specific time point after administration of 120 ml.
- The late-phase pharmacokinetics of iopromide are comparable to those of iohexol and Tc99m-DTPA.
Objective:
The pharmacokinetics of iopromide were analysed using a two-compartment model. The optimal point of time for blood withdrawal for calculation of a one-sample clearance was determined.
Methods:
Plasma concentration of iodine was measured up to 8 h postinjection (p.i.) in 62 adult patients who received 120 ml iopromide for computed tomography (CT). A two exponential function was fitted by a weighted least error square method. As reference method, clearance was calculated from this function and the injected amount of iodine. Empirical parameters for calculation of one-sample clearance were determined. This one-sample clearance was compared with one-sample clearance calculated according to formulas developed for Tc99m-DTPA by Jacobsson as well as a two sample method.
Results:
Total distribution volume of iopromide was calculated as 0.242 Lkg(-1)+/- 5.9%. A high correlation of all one-sample method and the two-sample method with reference to clearance was found. Best estimation of iopromide plasma clearance was achieved by determining one-sample clearance 270 or 285 min p. i. with SD(y.x) of 5.8 ml min(-1).
Conclusions:
After administration of 120 ml iopromide, one-sample plasma clearance can be calculated with low estimation error taking one blood sample at an appropriate time point. Late phase pharmacokinetics of iopromide found in the present study showed to be virtually identical to results published for iohexol and Tc99m-DTPA.
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