Chapter 170 - hemostatic drugs

Question 1

EACA and TXA drug class

Answer 1

synthetic lysine analogs - antifibrinolytic drugs

Question 2

EACA MOA

Answer 2

reversibly block lysine-binding site on plasminogen, inhibiting activation to plasmin by fibrin. plasmin breaks down fibrin into FDPs. at higher doses inhibits plasmin also

Question 3

why is use of antifibrinolytics contraindicated for treatment of severe upper urinary tract obstruction?

Answer 3

urinary tract obstruction may occur

Question 4

general contraindications to use of antifibrinolytics

Answer 4

prothrombotic disease processes (DIC, aortic thromboembolism, IMHA, hyperadrenocorticism)

Question 5

why aren’t antifibrinolytics commonly used in cats?

Answer 5

minimal data to support their safety, some experimental studies report seizures, myocardial injury and other adverse effects

Question 6

adverse effects of EACA in humans

Answer 6

dose dependent - hypotension, nausea, vomiting, diarrhea, generalised weakness, myonecrosis with myoglobinuria, rhabdomyolysis

Question 7

EACA metabolism

Answer 7

65% excreted unchanged by kidneys, 30-35% metabolised by liver to adipic acid, excreted by kidneys

Question 8

EACA half-life

Answer 8

1-2h in human adults

Question 9

TXA MOA

Answer 9

same as EACA (reversibly block lysine-binding site on plasminogen, inhibiting activation to plasmin by fibrin. plasmin breaks down fibrin into FDPs. at higher doses inhibits plasmin also) PLUS inhibits activation of trypsinogen and inhibits trypsin and thrombin