Summary
The effect of cimetidine and ranitidine on the fibrinolytic activity in vitro was
tested. The inhibition rate of spontaneous lysis rose proportionally to the increasing
drug doses. However, a similar effect was obtained with two other drugs of different
chemical structures and pharmacological properties. Streptokinase activated fibrinolyse
was not affected by either of the drugs at any concentration. Nor was clot formation
affected in these experiment conditions.
The results of the tests in vitro indicate that inhibition of euglobulin fibrinolysis
by H2-receptor antagonists is not specific for these drugs and not connected with their
pharmacological properties. It is possible to assume that, during therapeutic use,
cimetidine and ranitidine have no antifibrinolytic effect. Possible explanation and
relevance of these observations are discussed.
Key words
Fibrinolytic activity - Clot structure - H
2-receptor antagonist
