Final answer:
Antidotes for tPA, streptokinase, and urokinase toxicity include aminocaproic acid and tranexamic acid. These antidotes work as antifibrinolytics, inhibiting the activation of plasminogen and the subsequent breakdown of fibrin clots, thus mitigating excessive bleeding caused by thrombolytic therapy.
Step-by-step explanation:
You asked for information on the antidotes or treatments for tPA, streptokinase, and urokinase toxicity, and how they mitigate the toxic effects of these substances. Thrombolytic agents like tPA (tissue plasminogen activator), streptokinase, and urokinase work by breaking down clots, which is critical in the treatment of thrombotic stroke if administered within 3 hours after the event. However, their use can be associated with toxicity, primarily due to excessive bleeding.
Aminocaproic acid is an antidote that can be used to counteract the bleeding caused by these thrombolytic agents. It works as an antifibrinolytic, meaning it inhibits plasminogen activation, thereby preventing the breakdown of fibrin clots.
In addition, tranexamic acid may also be used to manage bleeding, acting in a similar antifibrinolytic capacity to aminocaproic acid. Treatment with these antidotes should be carefully monitored because they can increase the risk of thrombosis. Thus, the risks and benefits must be carefully weighed in patients being treated for thrombolytic toxicity.