Dose-Dependent Influence of Acetylsalicylic Acid on Platelet Functions and Plasmatic Coagulation Factors

Abstract

Lysine salt of acetylsalicylic acid (ASA) was given to ten patients by intravenous infusion. Blood samples taken at intervals during the infusion permitted the examination of the influence of the dose of ASA on platelet functions. Aggregation was significantly reduced when 50 mg ASA had entered circulation, while a diminution of PF 3 and PF4 availability could only be demonstrated when the dose had reached 500 and 200 mg, respectively. In order to exclude a longer latency time for the diminution of PF 3 and PF 4 availability, a second series of ten patients received intravenous injections of 100 and 300 mg ASA, respectively. From these patients, blood was taken 1 h after the injection. The decrease of PF 3 and PF 4 availability in these cases was comparable to the results of the first group. In a third series of patients, a daily intravenous dose of 2,000 mg ASA was given. In these cases, a moderate decrease of factors II, VII, IX and X was observed. Since the appearance of a PIVKA effect could also be demonstrated, vitamin K antagonism was assumed when a high dose of ASA was given for an extended length of time.

Platelet-Active Drugs: The Relationships Among Dose, Effectiveness, and Side Effects

“…These effects include the dose-dependent inhibition of platelet function, 74 -78 the enhancement of fibrinolysis, 79 -81 and the suppression of plasma coagulation. [82][83][84][85] In contrast to the saturable and well-characterized (nanomolar aspirin concentration, rapid time course, physiologic conditions, and single serine modification) inhibition of COX-1 by aspirin, 86,87 the putative mechanisms underpinning the non-PG effects of aspirin on hemostasis are dose-dependent and less clearly defined. For example, the inhibition of shear-induced platelet aggregation depends on the level of aspirin provided, and enhanced fibrinolysis due to N-acetylation of lysyl residues of fibrinogen is seen in vivo with high doses of aspirin (650 mg twice daily) 79 and proceeds more rapidly in vitro under nonphysiologic alkaline conditions.…”

Reduction of daily life ischaemia by aspirin in patients with angina: underlying link between thromboxane A2 and macrophage colony stimulating factor

“…12 Randomisation to aspirin or placebo Aspirin and placebo were provided by the hospital pharmacy as identical capsules. Aspirin was given at a dose of 300 mg/ day because, at this dose or higher, studies have shown that it may inhibit shear induced platelet activation 13 and thrombin generation, 14 and exert an anti-inflammatory effect. 15 Each treatment lasted three weeks to avoid any carry over effects of aspirin.…”

Trauma and Acetylsalicylic Acid-Induced Changes in Hemostasis during Liver Resection in the Rat

“…This was due to results showing the inhibitory effects o f the drug on platelet aggregation and plasmatic coagulation factors (21,23,28). However, at present there is no conclusive evi dence that drugs altering platelet function, such as A SA , dipyridamole and sulfin-pyrazone, have any significant effect on posttraumatic platelet aggregate formation and its complications (17).…”