Influence of some vasoactive drugs on fibrinolytic activity.

ARECENTLY published tabulation' of simple organic compounds reported to induce some weak fibrinolytic activity includes only compounds known to influence vasomotion (procaine, epinephrine, diethylaminoethanol). Studies in our laboratory concerning the influence of vasomotor drugs on the clotting mechanism have resulted in the observation that intravenously administered nicotinic acid induces rather strong fibrinolytic activity.2 This paper presents data on the influence of representative vasomotor drugs on the clotting mechanism, and particularly on fibrinolysis. METHODS Rates of peripheral blood flow were measured in man in a constant temperature-constant humidity room by methods previously described.3 Clotting tests included 1-stage prothrombin time (whole and diluted plasma),4 recalcification time,5 antithrombin activity6 and fibrinolytic activity, both by test tube observation7 and the coagulograph ("thromboelastograph" of Hartert).8 9 Drugs studied in man included nicotinic acid (orally, intravenously, intramuscularly, and intraarterially), nicotinamide (intravenously), calcium gluconate (intravenously), diethylaminoethanol (intravenously), histamine (intravenously), papaverine (intravenously and intra-arterially) and llidar (intra-arterially).