[Pharmacokinetics of cyclosporin A in patients with nephrotic syndrome]

The pharmacokinetics of Cy A have been studied in patients with N.S.. Eight patients (7 M, 1 F) received a single 12.5 mg/kg oral dose and a single 4 mg/kg intravenous dose. Plasma was separated from red blood cells at 22 degrees C, at least 2 hr after drawing. Cy A plasma levels were determined by reverse HPLC. The comparison of our pharmacokinetic parameters for the oral route with those from reference patients showed significant differences for T1/2 Ka and Tmax which were decreased in N.S. For the I.V. route we found a decrease in total plasma clearance (CLTP). Absolute bioavailability (18%) was also diminished. Moreover total cholesterol and B apolipoprotein were increased in our nephrotic population. Cy A is highly bound to lipoprotein and we found a significant negative correlation between CLTP of Cy A and either B apolipoprotein or total cholesterol. We conclude that the increase of lipoprotein in N.S. is probably responsible of the modifications in pharmacokinetics of Cy A. Nevertheless Cy A dosage can be not modified in N.S. when oral route is used and divided by a factor two for the I.V. route.