Dose-effect and pharmacokinetics of estrogens given to correct bleeding time in uremia

Conjugated estrogens have a significant and long-lasting effect in shortening bleeding time in patients with end-stage renal disease. The studies so far available indicate that repeated estrogen administrations are necessary to short bleeding time in uremia in a dose range of 95 to 325 mg. With the present study we wanted to establish whether single or repeated doses are required to induce a significant shortening of bleeding time in uremia, and the minimum cumulative dose of conjugated estrogens necessary to control bleeding time for a prolonged period of time, and to check whether the prolonged effect of estrogens on bleeding time in uremia is due to an accumulation of the drug or its metabolites in the blood. Fifteen uremics on chronic hemodialysis were studied. A pilot study carried out in five uremic patients indicated that single or repeated estrogen infusions of 0.3 mg/kg did not significantly influence bleeding time values. Therefore the subsequent studies have been carried out using daily infusion of 0.6 mg/kg. A single estrogen infusion of 0.6 mg/kg shortened bleeding time in all patients. The effect was transient and bleeding time returned to pre-infusion values within 72 hours. A 50% decrease of bleeding time or a shortening of bleeding time more than 30 to 15 minutes or less was obtained in all patients with four or five infusions (0.6 mg/kg) spaced 24 hours apart. The effect lasted for 14 days. At day 25 from the last infusion all the patients had bleeding time values comparable with the pre-infusion ones.(ABSTRACT TRUNCATED AT 250 WORDS)