Pharmacokinetics of Dextran-70 in patients with cirrhosis and ascites undergoing therapeutic paracentesis

Dextran-70 is frequently used as a plasma expander in patients with cirrhosis treated with large-volume paracentesis to prevent post-paracentesis hypovolemia, which is thought to develop after 24 h following the procedure. However, there are no studies on Dextran-70 pharmacokinetics in cirrhosis.

Nine patients with alcoholic cirrhosis and tense ascites treated with a 5-1 paracentesis were given 500 ml of Dextran-70. Blood samples to measure the plasma concentration of dextran were obtained 15 and 30 min, 1, 2, 3, 6, 12 and 24 h and 2 and 6 days after the end of the infusion. Nine healthy volunteers were studied in identical fashion after infusion of 100 ml of Dextran-70. The plasma concentration of dextran was determined by the anthrone method. A bicompartmental model was used to analyze the pharmacokinetic parameters.

There were no significant differences between patients with cirrhosis and controls in the volume of distribution (7.7 +/- 0.6 vs. 7.3 +/- 1.21), half-life of the first and second component of plasma disappearance (2.96 +/- 0.69 and 80.3 5.9 h in patients with cirrhosis vs 2.82 +/- 0.69 and 67.1 +/- 10.7 h in controls).

The pharmacokinetics of Dextran-70 in patients with cirrhosis and ascites after large-volume paracentesis is similar to that in controls. This may explain why Dextran-70 is less effective than albumin in preventing paracentesis-induced hypovolemia, which starts after most Dextran fraction has disappeared from plasma.