Pharmacokinetics of recombinant activated factor VII in trauma patients with severe bleeding.

INTRODUCTION: Recombinant activated factor VII (rFVIIa) has been used as adjunctive therapy in trauma patients with severe bleeding. However, its pharmacokinetics profile remains unknown. METHODS: In two placebo-controlled studies in patients with blunt and penetrating trauma, the pharmacokinetics of rFVIIa given at an initial dose of 200 microg x kg-1 after transfusion of eight red blood cell units, followed by additional doses of 100 microg x kg-1, one and three hours later, have been studied, based on the FVII coagulant activity assay. Both non-compartment and population pharmacokinetic analyses were performed. A two-compartment, population pharmacokinetic model was used to estimate a population profile for the rFVIIa dosing regimen. Data are population means (percent coefficient of variation (CV)). RESULTS: Based on the two-compartment population model, the estimated pharmacokinetic parameters were: clearance 40 (30% CV) ml x kg-1 x h-1; central volume of distribution 89 (32% CV) ml x kg-1; inter-compartmental clearance 24 ml x kg-1 x h-1; and peripheral compartment volume 31 ml x kg-1. Baseline FVII coagulant activity was estimated at 0.29 (39% CV) U x ml-1, initial half-life was 0.6 (34% CV) hours, and terminal half-life 2.4 (50% CV) hours. High intra- and inter-patient variability was noted in volume of distribution and clearance, which was in part correlated with the transfusion requirements as the single significant covariate. The non-compartmental analysis led to almost identical estimates of key parameters. CONCLUSION: A high intra- and inter-patient variability was noted in the volume of distribution and clearance of rFVIIa in trauma patients with severe bleeding, mainly related with the transfusion requirements and thus blood loss and/or bleeding rate.

The Pro12Ala variant of the PPARG gene is a risk factor for peroxisome proliferator-activated receptor-gamma/alpha agonist-induced edema in type 2 diabetic patients.

CONTEXT: Activation of peroxisome proliferator-activated receptors (PPARs)-gamma by thiazolidinediones (pioglitazone, rosiglitazone) and dual-acting PPARalpha/gamma agonists (pargluva, ragaglitazar) is a widely used pharmacological principle to treat insulin resistance and type 2 diabetes. Clinically, however, fluid retention and edema are worrying side effects with these drugs. OBJECTIVE: The objective of the present study was to investigate any variation in the PPARG and PPARA genes associated with the risk of fluid retention and development of peripheral edema in patients with type 2 diabetes treated with the dual-acting PPARalpha/gamma agonist ragaglitazar. DESIGN: Single-nucleotide polymorphism and haplotype analyses of the PPARA and PPARG genes were performed on DNA obtained from 345 type 2 diabetic patients randomized to 26-wk monotherapy with the dual-acting PPARalpha/gamma agonist ragaglitazar. RESULTS: At 26 wk, edema was recorded in 48 of the patients (14%) treated with ragaglitazar, and Cox regression analyses identified the common Pro12Ala variant of the PPARG gene as biologically the most important risk factor (hazard ratio 4.42, P = 0.0081) for edema. Other risk factors included female gender (hazard ratio 3.34, P = 0.0005) and weight change during treatment (hazard ratio 1.20, P = 0.0017). CONCLUSIONS: A population-attributable risk of approximately 50% for the Pro12Pro genotype indicates that testing for the Pro12Ala of the PPARG gene in addition to the already identified clinical risk factors may become a useful tool to further reduce the risk of PPARgamma agonist-induced fluid retention and edema in patients with type 2 diabetes.