PHARMACOKINETICS OF GD-DTPA IN PATIENTS WITH CHRONIC-RENAL-FAILURE

We investigated the pharmacokinetics of dimeglumine gadopentetate (Gd-DTPA), a contrast agent for magnetic resonance imaging (MRI), in 24 patients with chronic renal failure whose creatinine clearance ranged from 7.2 to 70.0 mL/minute (median 25.4 mL/minute). After single intravenous administration of 0.1 mmol/kg, the serum levels of Gd-DTPA were monitored up to five days and urine and feces were collected quantitatively up to two days. The pharmacokinetic parameters were calculated from the concentration-time profile in the serum and urine using an open two-compartment model. No changes in the volume of distribution (V(c) and V(area) or in the half-life of distribution were found for patients with chronic renal failure as compared to patients with normal renal function. However, in correlation with the reduced glomerular filtration rate in patients with chronic renal failure, the half-life of elimination was prolonged and serum and renal clearance were decreased. The recovery of Gd-DTPA in urine was 92.1% +/- 12.1% of the dose administered, and extrarenal elimination was less than 0.4%, indicating that glomerular filtration remains the predominant route of elimination. Only for patients with highly impaired renal function (creatinine clearance < 20 mL/minute) was the recovery in the urine less than complete.