In 6 normal volunteers given single oral doses of 250,500 and 1000 mg ticlopidine (T), the peak plasma level of unchanged drug was reached after about 2 h. There was no correlation between the plasma T level and its inhibitory effect on platelet function, expressed as % inhibition of ADP-induced aggregation. By means of HPLC and GC/MS significant concentrations of T were demonstrated in washed red cells, platelets and neutrophils, with a marked difference in the time course of the appearance of cell-associated drug. The time course of platelet-associated T very accurately fitted that of the antiaggregatory activity. After subacute oral administration (250 mg b.d. for 7 days), the maximum effect on platelet function was observed after 3 to 4 days, when a significant concentration of platelet-associated T had been reached. The pharmacological effect persisted as long as drug was detectable in platelet. An in vitro study strongly suggested that the antiaggregating effect was retained by treated washed platelets but not by treated plasma. It is suggested that the platelet compartment represents the pharmacological target of T via a specific uptake system.
Because of its pathophysiological and clinical peculiarities, true menstrual migraine (MM) (i.e. migraine starting exclusively between the days immediately before and immediately after the first day of the menstrual cycle) requires an ad hoc management different from that of other migraines. The paucity of well-conducted, controlled clinical trials and the lack of a universally accepted definition of MM have meant that the treatment of MM is still largely empirical. In our clinical practice, we adopt a sequential therapeutic approach, including the following steps: (i) acute attack drugs (sumatriptan, ergot derivatives, NSAIDs); (ii) intermittent prophylaxis with ergot derivatives or NSAIDs; (iii) oestrogen supplementation with percutaneous or transdermal oestradiol (100 microg patches); (iv) antioestrogen agents (danazol, tamoxifen).
Twenty-four patients with vascular disorders, randomly divided into 3 dosage groups of 8 patients, were treated with a single oral dose of sulodexide (50, 100 or 200mg) and placebo. Tissue plasminogen activator (t-PA), plasminogen activator inhibitor (PAI-1) activity and antigen, euglobulin lysis time, α2-antiplasmin, plasminogen, fibrinogen, blood and plasma viscosity, and whole blood filtration rate were determined before administration and over the following 24 hours. Sulodexide significantly increased t-PA activity linearly with the dose over the range of 50 to 200mg. At the same time, it also significantly decreased the concentration of PAI-1 linearly and proportionally with the dose. No clear effects were observed on the other monitored parameters, although euglobulin lysis time and plasma viscosity showed a tendency to decrease after the administration of sulodexide. These results justify the clinical activity of sulodexide. Indeed, the concomitant increase of t-PA and decrease of PAI-1 activity and antigen might increase the natural fibrinolytic activity with a physiological potentiation, without other adverse effects. The known activity of sulodexide in decreasing plasma viscosity during long term treatment is, however, not immediately explicable by the single-dose effects.
Deep venous thrombosis is a common disease with significant danger of both acute and chronic complications. Widely accepted therapies are based on anticoagulant (heparin and/or anticoagulant agents) or early fibrinolytic therapy. All these therapies frequently have severe side effects. Defibrotide is a new drug with antithrombotic and profibrinolytic activities but without anticoagulant activity and major side effects. To evaluate the efficacy of this drug against acute thrombophlebitis, we treated a group of 10 patients with 200 mg defibrotide intravenously three times a day for 15 days. Fibrinolysis parameters were monitored every other day. The indices of venous function by strain-gauge plethysmography and venous occlusion were evaluated every 7 days.The drug induced a significant improvement in plethysmographic indices and a significant profibrinolytic activity. Defibrotide-treated patients showed a fast disappearance of clinical and instrumental signs of thrombophlebitis. No side effects were reported during the study.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.