Prophylactic doses of low molecular weight heparin (nadroparine): Chronopharmacological study after subcutaneous administration to healthy volunteers; [CHRONOPHARMACOLOGIE D'UNE HEPARINE FRACTIONNEE (NADROPARINE) ADMINISTREE PAR VOIE SOUS-CUTANEE A DOSE PROPHYLACTIQUE CHEZ LE VOLONTAIRE SAIN]

This study evaluated the effect of injection time on pharmacodynamic of a single subcutaneous bolus of nadroparine (7500 anti-Xa IC U) evaluated by anti-Xa activity (Hepaclot and Heptest) and by activated partial thromboplastin time (APTT by auto PTT reagent). 10 healthy male volunteers were studied at 4 different 24 hours periods with 4 different injection times (6 am, 12 am, 6 pm, 12 pm) and with a one week wash-out period between each period. No chronopharmacological variation of the anti-Xa activity evaluated by Hepaclot was found. However the anti-Xa activity evaluated by Heptest was higher at the sixth hour after 12 am injection (p = 0.0022). No difference on APTT values was observed whatever the injection time. So the injection time of nadroparine has a weak influence on anti-Xa activity and no effect on APTT; Before to conclude on the lack of chronopharmacological effect of nadroparine, it seems necessary to evaluate such a possibility with higher dosage, with sick and older sujets.